1018498_combined

Task Force on Fault Current Limiter Testing

Frank C. LambertGeorgia Tech - NEETRAC

&

Michael „Mischa“ SteurerCenter for Advanced Power Systems,

Florida State University, Tallahassee, FL

Presented at the 8th EPRI Superconductivity Conference Oak Ridge, TN, Nov 12, 2008

11/12/2008 FCL_Testing_TF_EPRI-SC_Lambert_Steurer_12nov2008 2

New IEEE Task Force

• Goal– Develop a guide for testing novel FCL technologies (SC and

non-SC)– Complements activities by CIGRE WG-A3.23

• Scope– Identify FCL testing requirements from a utility point of view– Identify specific testing needs regarding the different FCL

technologies (e.g. superconducting vs. power electronics)– Identify applicability of existing power equipment testing

standards– Recommend additional tests and testing procedures as needed– Identify gaps in availability of testing capabilities and recommend

power requirements for upgrading


New IEEE Task Force

• Approach– Study and review novel fault current limiter (FCL) technologies

for medium and high voltage systems.– Map testing requirements against the needs by different FCL

technologies– Map testing requirements against existing power equipment

testing standards– Map testing requirements against available laboratory

capabilities– Coordinate with other technical committees, groups, societies

and associations as required• Status

– New IEEE task force was approved by the IEEE Switchgear Committee in October 2008

– We still need participants!• First meeting possible during the Joint Technical Committee

Meetings in Atlanta (http://www.pestechnical.com) January 12 – 15, 2009

• Next regular meeting of the IEEE Switchgear Committee will be in Asheville, NC, May 3 – 7, 2009


NEETRAC Fault Current Limiter Needs Assessment Survey

• Goal– Help target and direct FCL development towards applications

with the maximum potential benefit for utilities• Approach

– NETRAC customer sponsored 10-page survey• Planning, Substation Engineering/Design• Operations/Maintenance• Protection & Control

– Individual utility responses will be collected and aggregated byNEETRAC

– Only composite results will be distributed to sponsoring NEETRAC members, survey participants, and CIGRE WG A3.23

• Status– Revisions of the survey questions are possible until mid of

January 2009– Interested parties please contact Frank Lambert

Email [email protected] 404-675-1855Fax 404-675-1820

Eighth Annual Superconductivity ConferenceCigre WG A3.23 Update

Ashok SundaramSenior Project Manager

[email protected]

(650) 855-2304

November 12th-13th, 2008Doubletree, OakRidge, TNHosted by DOE and ORNL

2© 2008 Electric Power Research Institute, Inc. All rights reserved.

“New” Cigre WG A3.23 on Application and feasibility of fault current limiters in power systems

• Met in Erlangen, Germany (near Nuremberg) hosted by Mr. Heino Schmitt of Siemens on Sept 3rd & 4th , 2008

• Twenty members selected worldwide to serve on this WG picked on a competitive basis from a large number of applicants

• Scope of the WG A3.23 is as follows:– Build on WG A3.10 and A3.16 and draw to a close A3’s

investigation into FCL’s– Location of FCL installation– Different type of FCL’s– Experience from former and new pilot projects– Feasibility of application of conventional and novel FCL’s– Acceptance issues and how to overcome them– Customer system requirements (fault level, insulation

coordination, power quality and stability)– Interactions with protection and other control and power devices– Potential economical savings (examples from utility experiences)


“New” Cigre WG A3.23 on Application and feasibility of fault current limiters in power systems

• Time Schedule – 3 years

• Deliverables:– Technical brochure and report in Electra– Sessions symposium papers as appropriate– Tutorial material (enhancing that available from previous WG’s)

• Next Meeting– Early March 2009 sponsored by Zenergy (formerly SCPower) in

South San Francisco for a 2 days followed by a field visit to SCE to observe testing of Zenergy Superconducting FCL at the “Avanti” circuit of the future.

– Non members of the WG are welcome to attend and provide input but cannot participate in voting on motions passed.


Reports from Cigre on Fault Current Limiters

• Cigre Technical Brochure No 239 (WG A3.10) December 2003.– Fault current limiters in electrical medium and high

voltage systems

• Cigre Technical Brochure No 339 (WG A3.16) February 2008– Guideline on the impacts of fault current limiting

devices on protection systems

HTS CablesStatus of Standards Work

David LindsaySouthwire Company

EPRI HTS ConferenceOak Ridge, TN

12 Nov 2008

IEEE (www.ieee.org)

IEEEPES – Power & Energy Society

ICC – Insulated Conductor CommitteeC22D

C22D – Superconducting CablesInactive past ~5 yearsRe-activated in Oct 2008Discussion Group = no formal task for standard development at this time.Chair = David Lindsay

Cigre (www.cigre.org)

Cigre – International Council on Large Electric Systems

Study Committee B1 – Insulated CablesTF B1.31 – Testing of Superconducting Cable Systems

Created August 20081 year durationProvide terms of reference of future WGConvenor = David Lindsay

Cigre guides for HV/EHV cable are typically used as base for new IEC standards.

Proposal for US Sub-Committee on

HTS StandardsFrom Lance Cooley

IEEE-CSC Standards ChairAnd Bill Hassenzahl

Past IEEE-CSC Standards Chair

IEEE-CSC Standards• IEEE Council on Superconductivity recognizes

and supports standards activities– Hosted discussions 2004-2007 that led to new IEC-

TC90 working group on HTS current leads– Acts as liaison between individuals, organizations

(EPRI, IEEE, NEMA, Labs, Companies), and countries (IEC, VAMAS, CIGRE)

– Request to IEEE-CSC from Japanese National Committee for US participation in further work

• Proposal: IEEE-CSC will continue support as a liaison until a more formal organization is formed and funding can be secured

JNC-IEC Proposal• At the Berlin IEC TC-90 meeting the JNC proposed the creation of

an ad hoc group to discuss the validity of the general requirements of HTS (document available). The result of voting was 3 agreements(Japan, Korea and Poland) and 2 abstention (Germany and China). So the ad hoc group became possible to start. Professor Osamura was nominated as the Rapporteur. His comments to LD Cooley of the IEEE-CSC were:

• 1) The group should be organized by the experts from USA, Germany, Poland, China, Korea Japan and possibly others.

• 2) I feel this is very tough job for getting any reasonable conclusion whether its creation is valid or not.

• 3) So I would like to collect comprehensively opinions from the experts and also from people relating to SC science and technology. Please give me your opinion on this matter. And I would like to ask you to recommend the experts from USA.

• Cooley replied that we need to have general discussions in the USA and that we would provide a formal response in December 2008.

New IEC Ad-Hoc Group

October 9, 2008 Secretary IEC/TC90

Ad-hoc Group – 3: Standardization of Superconducting Wires Task: To study standardization issues on Superconducting wires and to report a result at the next TC90 meeting Member e-mail address Kozo Osamura (Japan) - Rapporteur

[email protected]

Koichi Nakao (Japan) [email protected] Jeonwook CHO (Korea) [email protected] Jacek Sosnowski (Poland) [email protected] TBD (USA) TBD (China)

Cooley (as of 11/7/08)

Motivation

• Groundwork by EPRI, IEEE-CSC, AEA DOE and others is working towards defining an effective organization

• Activity in, and request from, Japan requires a response at some level

• HTS conductors are becoming defined; end uses are developing; products are not yet there --- ripe for groundwork.

Potential US Committee Members approached by Cooley

• DOE: Haught• IEEE-CSC: Cooley, ‘Levy’• EPRI: Eckroad• NIST: Goodrich• NEMA: Liebowitz• AFRL: Barnes• NRL: Gubser

• NHMFL: Larbalestier• ORNL: Lee• LANL: Marken• GE: Bray• AmSC: Maguire, Fleshler• SuPwr: Xie, Martchevskii• AEA: Hassenzahl

Action items for coming year• Hold a workshop• Define an organizational structure• Prepare a Formal US response to JNC-IEC• Seek support• Assess landscape and needs

– Current leads already in progress– “WG1” – begin work on terminology– “WG2” – some characterizations need standards– Activities by CIGRE, EPRI, NEMA…

USA Formal Response to JNC• Details TBD• Suggest forming an ad hoc committee (following the IEC

plan) within the US with some or all of the individuals listed above.

• Suggest that the chair be from the IEEE-CSC and that this organization act as a coordinator for activities.

• During a workshop early in 2009 determine areas where standards are needed, both now and in the future.

• Address national and international issues in the standards area and how to establish a level playing field.

An Assessment of Fault Current Limiter Testing Requirements

Brian Marchionini &Ndeye K. Fall Energetics Incorporated

Dr. Michael “Mischa” Steurer Florida State University

EPRI Superconductivity Conference, November 12-13, 2008

What is a FCL and How Does it Work?

Fault

Very Low Impedance

Project Purpose and Scope

• Identify testing requirements for advanced electricity-delivery devices such as fault current limiters

• Make an assessment of the existing capabilities of testing facilities in the U.S. and internationally

• Perform a gap analysis to determine where existing testing capabilities and facilities fall short

• The scope of the project includes solid-state and superconducting-based fault current limiters

• Focuses on projects sponsored by the U.S. Department of Energy

Methodology

Testing NeedsTesting NeedsTesting Facility

CapabilitiesTesting Facility

Capabilities

Gap AnalysisGap Analysis

Subject Matter Expert InterviewsSubject Matter Expert Interviews

Organizations Contacted

Electrivation

Types of Testing

Specialized tests designed to obtain specific information.

Field tests during the lifetime of a system to detect deterioration.

IEC definition – “A test made before supplying of a general commercial basis of a system in order to satisfactory long term performance of the complete system.”

Verify that the device meets specifications before leaving the factory.

Tests performed to detect shipping or installation damage. Also reveals defects in workmanship.

Performed to demonstrate the adequacy of designs and materials of a system. Generally required when there is a significant change inmaterials or the manufacturing process.

Electrical and mechanical tests performed in a laboratory and conducted during development.

Description

Special-Purpose Tests

Maintenance Tests

Long-Term Prequalification Tests

Factory Production Tests

xCommissioning Tests

xType Tests

xResearch and Development Tests

Immediately needed

Category

Based on Table 3-2, on test categories for underground cable in EPRI Specifying and Testing HTS Power Equipment (Report number TBD)

Specifications for DOE’s FCL Projects

TransformerTransformer, Reactor, and Circuit Breaker

Transformer, Reactor, and Circuit Breaker

Cable, TransformerTesting Protocol Basis

20% to 40% reduction of a 60 kA to 80 kA fault

20%–50% reduction

50% reduction of an 80 kA fault

20–50% Reduction – 37 % at SCE (63 kA to 40 kA)

Fault Current Reduction

138 kV; 2,000 to 4,000 Amps steady-state; 3-phase

138 kV; 1200 Amps; 3-phase

69 kV; 3,000 Amps; 3-phase

138 kV, 2000 A Class (115 kV, 1200 Amps at SCE site); 3-phase

Ratings (final design)

• DC-based iron core• One DC first-generation HTS coil for a three-phase AC FCL• Saturable reactor-type FCL• Suitable for 2G materials, when available

• Resistive FCL• Matrix design has parallel, 2G HTS elements and conventional coils

Uses high power semiconductors Super-gate turn-off thyristor (SGTO)

• Resistive FCL• 3-phase, transmission voltage• Low-inductance bifilar coil switching module technology using 2G wire

Design

Zenergy PowerSuperPowerSilicon PowerAMSCSpecification

Current Status and Future Requirements of FCLs

0.1 1 100.1

1

10

100

Resistive HTSSaturated Iron CoreSolid State

Rated Current / kA rms

Line

-Lin

e V

olta

ge /

kV rm

s

AMSC

AMSC

Silicon Power

Zenergy

Silicon Power

Zenergy

SuperPower

SuperPower

Transmission

Distribution

Full Scale

Current Status

Examples of Test Facility Capabilities

Variable frequency and voltage converter

6.2 @ 4.161.5 @ 0.48

N/A4.160.481.15 (DC)

1.7134.8 (DC)

60 Hz power system grid fed from 12.47 kV

7.5 @ 4.161.5 @ 0.48

1300.3850.484.16

84137

0.140.140.1Tallahassee, FL

Florida State University-CAPS

2.2 MV, 220 kJ Impulse generator1MV Cascade Transformer

N/AN/A.1225 for 2 s1.002.201.00Atlanta, GANEETRAC

Short-circuit generator rated 4800 MVA at 18 kV

1000 MVA at 18 kV

4800 MVA24, 48, 72, 96 kV

154 kA @ 50/60 Hz at 18 kV

400 kV, 10 mA

4200 kV, 50 µs

400 kVChangwon, Korea

KERI

13.4-kV power grid; 1400 MVA generator

5 @ 13.4400 for 1 s

14004 (100 for ~1 sec. with upgrade)

0.025N/A0.138 (with upgrade)

Los Alamos, NM

LANL

DC and AC power suppliesN/AN/A0.3 (0.6 with upgrade)

500.30.8 0.2Oak Ridge, TN

ORNL

Power system grid (12,000 MVA)N/A150013.6110 for 3 s.1.003.000.80Vancouver, Canada

Power Tech

4 short-circuit generators, 2,100 MVA each

N/A840015 @50Hz17@60Hz

390 for 0.42 s.

1.002.601.00Arnhem, The Netherlands

KEMA

Short-circuit generators rated for 1,000 and 2,250 MVAparallel operation possible

N/A3250 13.850 for 1 s63 for 0.5 s.

0.100.800.55Chalfont, PAKEMA

Continuous Power

(MVA) @ nominal

voltage (kV)

Maximum (Surge) Power Rating (MVA)

No-load voltage (kV)

FaultDCLightning Impulse1/2/50μs

AC 50/60 Hz

Kind of Source(s) for the LabHigh-Power TestCurrent Test (kA) at “zero” voltage

Insulation Test (MV) at “zero”current

LocationName

Limited Current (kA)

Vol

tage

acr

oss

FCL

(kV

)

0

20

40

60

80

0 10 20 30 40 50 60 70 80 90 100

Testing Facility Gaps

SuperPower 90kA Prospective Fault with 50% reductionSuperPower 90kA Prospective Fault with 25% reduction

Source Capacity KEMA Holland

Source Capacity KEMA PASource Capacity PowerTech

Silicon Power 80 kA Prospective Fault with 25% reductionSilicon Power 80 kA Prospective Fault with 50% reduction

Zenergy 80 kA Prospective Fault with 50% reductionZenergy 80 kA Prospective Fault with 25% reduction

Source Capacity KEMA Holland with Ideal 4x Transformer

Major Findings – Part 1• T&D equipment testing facilities can provide voltage and

current to adequately test FCLs at the distribution level• There is no place that has the capabilities to test FCLs at

transmission-level current and voltage levels simultaneously

• While there is a need to conduct high voltage-current tests, “synthetic tests”, similar to the one’s used for circuit breakers, may be sufficient for certain tests

• There are a number of experts who believe advanced modeling and simulation may possibly substitute for certain tests

Zenergy’s FCL Device

Major Findings – Part 2• Commercial testing facilities are not always conducive for

advanced design and prototype testing for R&D projects

• Commercial T&D equipment testing facilities tend to be costly, busy, and difficult to schedule

• There are approximately 100 testing facilities around the world and these are equipped and managed to conduct routine tests of existing or market-ready devices to meet known standards and protocols

AMSC’s FCL module testing

Major Findings – Part 3• Today there are no common guidelines for testing

prototype high-temperature superconducting (HTS) and solid-state FCLs and for integrating these devices with the electric system

• Testing procedures have been and will continue to be developed by FCL device manufacturers and their utility R&D partners and will vary depending on the design of the equipment and the application

• This lack of standards complicates the testing process as each trip to the testing facility has unique requirements, protocols, and procedures

• The existence of standards could help expedite and accelerate the testing process

Conclusions• There is a need for testing facilities that have the flexibility

to respond to the special requirements of R&D projects• Given the unique capabilities of fault current limiters there

is an expectation that utilities will allow prototype FCLs to be installed and tested on their own systems, before they have been simultaneously tested for high current and high voltage

• There is a need to continue the discussionon FCL testing recommendations

SuperPower’s FCL module testing

Questions?

Brian [email protected]

Michael “Mischa” [email protected]

Calculating required voltage

• System impedance w/o FCL (Ω1)= Single phase voltage/Fault current

• Required FCL impedance (Ω2)= Single phase voltage/Limited fault current

• Required voltage drop = (Ω1-Ω2) X Reduced fault current

Ashok SundaramEPRI

[email protected](650) 855-2304

Development of Test Protocol for 15kV Class Solid-State

Fault Current Limiter

Mahesh GandhiSilicon Power [email protected](484) 913-1520

2

© 2007 Electric Power Research Institute, Inc. All rights reserved.Silicon Power Corporation Proprietary

9:30AM – 10:00AM

• SSCL Program Overview Ashok Sundaram

• SSCL Test Protocol Mahesh Gandhi

– SSCL design

– SSCL field test circuits

– SSCL test protocol

• Performance Verification testing at KEMA

• Pre-connection test (dielectric, partial discharge, etc.)

• Field operations testing (Steady-state test & Transient performance)

3


DSTATCOM

ENERGYSTORAGE

SOLID-STATEBREAKER

SSCL

DVR

ENERGYSTORAGE

SSTS

DYNAMICNON-LINEAR

LOAD

SENSITIVELOAD

CRITICALLOAD

UNINTERRUPTEDSUPPLY

REDUCEDSAGS, TRANSIENTS,

HARMONICS

SENSITIVE LOAD

COMPENSATEDVOLTAGE, POWER FACTOR

HARMONICS,

EPRI’s Smart Grid Power-electronic based Technologies

IUT RESIDENTIALLOAD

4


Fault Current Management

• Growth in the generation of electrical energy and an increased

interconnection of the networks and distributed generation leads to

higher fault currents

• Higher fault causes more stress on the system reducing the life of

critical components such as transformers and has adverse impacts

on grounding.

• The growth in capacity requires replacing existing circuit breakers

with higher fault current ratings. Major cost impact and down time.

5


Pat Duggan - ConEdison

“Fault Current Limiting functionality is a critical enabler for ‘open

access’ for new transmission and generation, and more cost effective

infrastructure upgrades and replacements. In addition fault current

limiters can mitigate recovery time of superconducting cables and

give selected DGs an advanced option to serve peak loads after

external faults.”

6


FCL Technology Taxonomy

• Splitting into sub grids

• Introducing a higher voltage range

• Splitting of bus bars

• High impedance transformers

• Current limiting reactors

novel concepts

• Superconductors

• Semiconductors

• Hybrid systems

Topologicalmeasures

Apparatusmeasures

Permanent impedance increaseduring nominal and fault conditions

Condition based impedance increaseSmall impedance at nominal loadfast increase of impedance at fault

• Fuse based devices(< 36 kV)

• Stand alone HV fuse(< 1 kA)

• Commutating Current Limiters (< 5 kA)

• Sequentialtripping

Old term:“passive” Old term:

“active”

Apparatusmeasures

Topologicalmeasures

New terminology as defined in previous EPRI FCL study now adopted by CIGRE WGa3.16

7


69 kV SSCL EPRI / DOE

• SSFCL looks like a Transformer

– Tank Size - 12’h x 12’w x 12’d

• OFAF Cooling System

– Size - 10’h x 5’w x 7’d

• Total weight – 80,000 lbs

• Local / Remote Control

Outline of 69kV, 1000A, 1Ph Unit

8


15 kV 1200A SSCL CEC/SCE/EPRI Project

Voltage Class 15 kV

Number of phases 3

Frequency 60 HZ

Current rating 1200 A

Fault current 23 kA

Let-thru current 9 kA

Let-thru current duration 30 cycles

BIL rating 110 kV

Size 12’ H 11’ W 12’D Weight 40 000 lbs

9


SSCL Program Team

• DOE / Washington HQ - Gil Bindewald

• DOE / Chicago - Stephen Waslo

• EPRI Project manager - Ashok Sundaram

• Villanova University - Dr. Amy Fleischer

• SSCL Developer - Silicon Power Corp.

• SSCL Commercializer - Howard Industries

• Technical Consultant - Dr. Laszlo Guygyi

• Utility Advisor’s - Pat Duggan (ConEd)

- Pat Dilillo (ConEd)

- Sanjay Bose (ConEd)

EPRI P37D Task Force on Advanced Solid-State Substations Techniques

Chair: Jim Houston – Alabama Power Company

10


Current Limiting Effect

2007 R&D100 Award Winner SGTO Device

- Performance Driver

11


SSCL Concept

• Design Features:– No cryogenics– Immediate recovery– Fail safe – No current distortions– SuperGTO

• Lower losses• Reduced Overall size and

weight• Modular design expandable to

desired Voltage & Current Ratings

Main SGTOswitchiLINE

Varistor

Line reactance

Auxiliary SGTO switch

Commutation Capacitor

Commutation Inductor

Limiting Inductor

Circuit Breaker

Operation:

• Normally the continuous current flows thru the fast speed switch (Main SGTO).

• Once the fault is sensed by high-speed sensor and declared by FPGA board, the current is commutated to Limiting Inductor (CLR).

• Introduction of CLR will limit the current to the level below the rating of the downstream breaker. The downstream breaker will trip and open the ckt within 30 cycles.

12


VLC – Voltage Level Controller

SSCL Architecture

13


SSCL Design

Standard Building Block• 44”L x 13”w x 15”h, 100 lbs

SGTO Module – 800A 5kV

Power Stack• 90”h x 66”w x 46”d• 1800 lbs

15kV 1200A Final Assembly• 11’h x 12’w x 12’d, 40,000 lbs

including Oil

14


SSCL Accessories

15


SSCL RatingsParameters 69kV 15kV

• Rated Maximum Voltage, kV rms 72.5 15.5• Rated Continuous Current, Ampere rms 1000 1200 4000• Rated Power Frequency 60 60• Available fault current, kA rms 80 23 11• Rated Let-thru Current, kA rms 40 9 5.5 • Rated Let-thru Current Duration, cycles 30 30• Rated Dielectric

– Power Frequency 1 min dry kV, rms 160 50 – Impulse, Full-wave Withstand, kV peak 350 110– Impulse, Chopped-wave Withstand, kV peak 452 142

• Ambient Temp, Degree C 40 / 50• Rated Control Power, V DC or AC, 60Hz, 1ph 125 DC 120 AC 125 DC• SSCL Power Efficiency 99.75%• Line Voltage drop 0.3%• Line Harmonic Distortion None• Partial discharge TBD 100 pC/19.5kV• Audible sound test TBD 55dBA/20’ 58dBA/6’

16


SSCL Field Test Circuits

17


Inherently Fault Current Limiting Cable + Stand Alone Fault Current Limiter Demonstration

Substation

Substation (new)

Generating StationStreet

Highway

Refrigeration


18


T1

CBT1SW

CBT1SE

CBT1W

CBT1ETo74440

T2

CBT2SW

CBT2SE

CBT2W

CBT2ETo74441

T3

CBT3SW

CBT3SE

CBT3W

CBT3ETo74442

T4

CBT4SW

CBT4W

CBT4ETo74443

CBT4SE

SSFCL

East 75th Street Substation

T1

CBT1SW

CBT1SE

CBT1W

CBT1ETo74416

T2

CBT2SW

CBT2SE

CBT2W

CBT2ETo74417

T3

CBT3SW

CBT3SE

CBT3W

CBT3ETo74485

York Substation

SSFCL

HTSCable

F8

SSCL Application In ConEd

One fault location

Most severe case

SSFCL in two locations

ConEd 138 kV system

equivalent from PSS/E data base

HTS cable PI circuit equivalent from

Southwire data sheet

19


SCE’s “Avanti” circuit a.k.a circuit of the future

VFI/Remote Controlled

Switch

Circuit Tie

Switch

Circuit Tie

Switch

Sweetwater 12KV

Northpark

12KVM

Typ. Load Transformer

ShandinSubstation

Tie RCS

RCI2

Tie RCS

Fiber Optic Duct temp Monitoring

SystemSolid State


Multi-Stage Capacitor Banks

TieRCS

RAR

DistributedGeneration

G

USAT

RCI3RCI

1

SCADA System Gateway

Comm.

Fiber

SEL 2100Logic Processor

Secondary Network

20


15kV 1200A SSCL Test Protocol

21


• Dielectric Test– Power frequency Voltage Withstand Test

– Full-wave lightning impulse withstand voltage tests

– Chopped wave lightning impulse withstand voltage tests

– Insulation test by power factor measurement (Dobble test)

– Insulation test by resistance measurement (Megger test)

– Partial Discharge Test

– CLR resistance & impedance measurement

• Current Limiting Test • Efficiency (power loss) Test (Steady state Operation test)• Continuous Current Carrying Test/ Temperature Test (Steady state

Operations test)• Audible sound test

Controlled Testing at KEMA Power Lab

22


• Tests at SSID facility:– Insulation test by power factor measurement (Dobble test)– Insulation test by resistance measurement (Megger test)– Partial Discharge test

• Tests at Shandin Sub-station:– Pre-connection testing

• Visual Inspection• Tank Pressure test• Insulation/Dielectric tests

– Insulation test by power factor measurement (Dobble test)– Insulation test by resistance measurement (Megger test)

– Field evaluation testing• Steady-State and Transient (at fault) performances

Tests at Southern California Edison

23


Power frequency Voltage withstand Test

• Tests SSCL dielectric integrity against the continuous operatingvoltages.

• 60Hz sine-wave voltage of rated amplitude is applied for 60seconds from SSCL line terminals to ground. Leakage current is monitored

• Wet test procedure - The wet tests are made only on outdoor SSCL or on external components such as bushings, in accordance with the procedure described in IEEE Std C57.19.00-1991.

Note: For those bushings, where their voltage distribution is negligibly influenced by their surroundings, and which have been tested separately as individual bushings in accordance with IEEE Std C57.19.00-1991, the tests need not be repeated on the assembled SSCL.

24


Power Frequency Voltage Withstand Test schematic

25


Full-wave Impulse withstand Voltage Test

• Tests to verify their ability to withstand their rated full-wave lightning impulse withstand voltages.

• Both positive and negative, lightning impulse voltages having a peak value equal or greater than the rated full-wave lightning impulse withstand voltage shall be applied between the terminals of the SSCL and the ground / case.

• Waveform for lightning impulse tests per IEEE Std 4

Positive Impulse Negative Impulse

26


Full Wave Impulse Test Schematic

AC

Source

27


Chopped-wave impulse withstand voltage Test

• To verify their ability to withstand their assigned rated chopped wave lightning impulse withstand voltage.

• The voltage shall be applied to the terminals of the SSCL, without causing damage or producing a flashover, following the same procedure as for full-wave impulse test.

• The waveform and application of the chopped wave test voltage, and the type of rod gap and its location, shall be as described in IEEE Std 4-1978

28


Schematic for Chopped Wave Impulse Test

29


Fault Current Limiting tests

• Objective: The current-limiting test of the SSCL is to demonstrate the current-limiting performance and the related capabilities.• Test set up:

• Adjust the source impedance and voltage such that it provides Available fault current at power factor of not to exceed 5.9% lagging, equivalent to X/R = 17 at 60 Hz (11kA @ 600V for AMSC 15kV SSCL)

• Operating condition:• Run SSCL at continuous current operation and limit current at fault• Close SSCL on fault and limit the let-thru current

• Test Sequence• Pilot shot at 25% of rated let-thru fault current• Intermediate shot at 40-50% 25% of rated let-thru fault current• Final shots at 100% of rated let-thru fault current

30


Efficiency tests

• Objective: The of the test is to evaluate the SSCL performance for power losses at various current levels.•Test conditions

• Input – At the lower end of operating voltage range and higher end of input frequency.• Output / load – At 25%/50%/75% and rated load current, and 0.85 lagging power factor.

31


Continuous Current / Temp Rise tests

• Test conditions

• Ambient – Room temp.

• Output – 3ph bolted short.

• Input Voltage – Variable low voltage enough to provide 25% and gradual rise to 50%-75% and finally to rated load current.

• Temp. Monitoring

• Built in Heatsink temp. sensors

• Cooling liquid temp (Top, Mid, and lower level)

• Tank (top, bottom, middle on both sides)

32


Pre-installation test

Visual Inspection

SSCL once received at site an external inspection of the SSCL tank and fittings will be done which will include the following points:

1. Is there any indication of external damage?

2. Is the paint finish damaged?

3. Are the attached fittings loose or damaged?

4. Is there evidence of fluid leakage on or around the tank coolers?

5. Are any of the bushings broken or damaged?

6. Is there any visible damage to the parts or packaging which shipped separately from the SSCL?

33


Pre-installation test

• Tank Pressure• The tank pressure may be positive or negative when received, depending on liquid temperature. In some cases, the vacuum pressure gauge may read zero, which could indicate a tank leak. In such cases, it is recommended to contact manufacturer before installation.

• Dielectric tests• Dielectric tests are the group of tests during which the SSCL will be subjected to higher voltage levels and therefore higher voltage stresses than would normally be experienced in service. The purpose is to confirm that the design, manufacture and processing of the SSCL and insulation structure and materials are adequate to provide many years of satisfactory life.• Recommended test is power frequency voltage withstand at reduced level to 75% of rating.

34


Field Performance Evaluation

• Objective: The objective of this test is evaluate the SSCL

performance in the field under Steady-State and transient condition

of the system in which the SSCL is connected.

•Test Monitoring:

• Steady state voltage and current sensors.

• High speed voltage and current sensors.

• Power Monitor and data recorder

• Temp. and Pressure Sensors

Steady-state and Transient Performance

35



SSCL

BYPASS SWITCH

Line

Breaker

No-load DISC.

SWITCH

SCE

15kV

LINE

SCE

15kV

LINE

Sequence of Operation: • Turn-ON: Close Bypass Switch. Close Load Disc Switch. Close Line Breaker. Open Bypass switch. Turn-on SSCL.• Turn-OFF: Turn-off SSCL. Close Bypass switch. Open Line Breaker. Open Load Disc Switch.

36



37


Real time monitoring and analysis

• Temp. Alarm

• Pressure alarm

• Power monitoring - V, I, kVA, KVAR

• Gas relay alarm

• Fault data records

SITE REQUIREMENT:

• AC Aux Power

• Internet Access

• Working Space

38


Thank you

1

Status of High Temperature Superconductor Cable and Fault Current Limiter Projects at

American Superconductor

J. F. Maguire and J. Yuan

EPRI Superconductivity ConferenceOak Ridge, TN

November 12-13, 2008

2

AgendaAgenda

• HTS Projects at AMSC• HTS Project Objectives and Milestones• Development Results of HTS Projects• Conclusions

3

HTS Projects at AMSCHTS Projects at AMSC

• Cable Projects- Transmission Voltage

• LIPA 1 (BSCCO Wires)• LIPA 2 (YBCO Wires)

- Distribution Voltage• Project Hydra Consolidated Edison

• Fault Current Limiter Project- Transmission Voltage

• Southern California Edison

4

Projects ObjectivesProjects Objectives

Demonstrate standalone HTS fault current limiter based on 2G wires in an operational power transmission grid. Introduce HV into FCL

FCL

Demonstrate HTS fault current limiting link between substations. Demonstrate feasibility of an underground installation of a fault current limiting HTS system in population condensed urban area

Hydra Project

Demonstrate a 2G HTS transmission cable and a cable joint in an operational power transmission grid. Demonstrate an FCL cable technology and repairable cryostat. Demonstrate modular refrigeration system.

LIPA 2

Demonstrate a transmission voltage level HTS cable and outdoor terminations in an operational power transmission grid

LIPA 1

5

Projects SpecificationsProjects Specifications

• 138kV/ 1200A

• Fault Current 63kA @ 4 line cycle (67ms)

• Fault Current reduction rate 36% (limit to 40kA)

FCL

• 320m long using YBCO wires

• 13.8kV/4000A, ~ 96 MVA


Hydra Project

• 600m long using YBCO wires

•138kV/2400A, ~ 576 MVA


LIPA 2

• 600m long using BSCCO wires

• 138kV/2400A, ~ 576 MVA


LIPA 1

6

Projects TimelinesProjects Timelines

FCL

HYDRA

LIPA 2

LIPA 1

2012201120102009200820072006200520042003Year

7

Project PartnersProject Partners

OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY

8

LIPA 1LIPA 1

Transmission Voltage Cable ProjectLong Island Power Authority

New York

Development Results of HTS ProjectsDevelopment Results of HTS Projects

9

LIPA 1 Project TeamLIPA 1 Project Team

10

Installation SiteInstallation Site

N

Holbrook Substation

Port Jefferson Shoreham

Wading River

MillerPlace

Terryville

Centereach Superconductor

11

Major Challenges of LIPA 1 ProjectMajor Challenges of LIPA 1 Project

• System Design- 138 kV, 2,400 amp operation- Survive 51 kA @ 200 ms fault- Manage Through-Faults- Manage larger cold contraction

• HTS Conductor Design- Handle real-world cabling stress using standard manufacturing

equipment

• Termination Design- Qualify to 138 kV operation, 650 kV BIL- Safely manage voltage breakdown- Manage results from loss of cryostat vacuum

World’s First Installation of a Transmission Voltage HTS Cable

12

LIPA 1 HTS Cable SystemLIPA 1 HTS Cable System

HV Termination

RedundantCooling & Control

Cold Termination

Bul

k LN

2S

tora

ge

Heat

Pow

er

SC

AD

A

Supply

Return

13

LIPA 1 HTS Cable DesignLIPA 1 HTS Cable Design

Copper Shield Stabilization

HTS-Shield

High Voltage Dielectric

FormerHTS Tape

Inner Cryostat Wall

Outer Cryostat Wall

Outer Cable Sheath

LN2 Coolant

14

Prototype TestingPrototype Testing

• A test program has been defined together with the DOE review team based on existing standards

• Tests included- High voltage dielectric

tests - High current tests- Hydraulic tests- Load cycles- Loss measurements

Type test performed prior starting manufacturing

15

PrePre--ConstructionConstruction

16

Installation Installation -- TerminationsTerminations

• Terminations were installed with the cable phase in place

• No issues identified during termination work

17

Installation Installation -- TerminationsTerminations

• Terminations were installed with the cable phase in place

• No issues identified during termination work

18

Installation Installation -- Cable PullingCable Pulling• Cable pulling operation was tested using a 70

meter long test setup to verify method and estimate force

• Cable puling on site was achieved without issues

• Vacuum level of cryostat was checked before and after pull

• Pulling force was recorded and compared to estimated values

Cable Pulling Force

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

0 100 200 300 400 500 600 700

Distance [m]

Forc

e [N

]

Phase 1Phase 2Phase 3

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

HTS cable distance in the PE pipe (m)

Forc

e (N

)

.

theoritical curve total (coeff0,24)therotical (rolls)

theoritical (cable in PE pipe)

19

Refrigeration substationRefrigeration substation

20

Cable cool downCable cool down

LIPA Cooldown Termination Temperature

50

75

100

125

150

175

200

225

250

275

300

0 48 96 144 192 240

Time (hours)

Tem

pera

ture

(K)

PT 101 PT 601 model model

Predicted

Actual

21

Cable Cable EnergizationEnergization• AC-High Voltage test

completed successfully- 1.5 Uo applied at each phase

for one hour- PD measurement completed

No partial discharge detected

• 24 hour dielectric soak test completed successfully

- Cable connected to LIPA grid at one end

• Cable connection at both ends completed on April 22nd

- Operation with parallel over-head line for 24 hours

- Operation without parallel path afterwards

Cable Commissioning Successfully Completed

22

Cable Operation Cable Operation -- MeasurementsMeasurements• The cable system is monitored

regarding a variety of parameters to- Ensure safe operation- Gain measurement data to

compare with design results• Measurement data analyzed so far:

- Cable cool down behavior - Cable cryostat thermal loss- Nitrogen pressure drop- Temperature increase due to

dielectric loss- Temperature increase due to AC-

loss- Thermal behavior of termination

(bushing)- Cable system time constants

Cable System Measurements in very good Agreement with Design Results

23

Steady State Operation (I)Steady State Operation (I)

0

10

20

30

40

50

60

70

80

90

7/2/08 12:00 AM 7/2/08 12:00 PM 7/3/08 12:00 AM

Tota

l MVA

0

50

100

150

200

250

300

350

400

7/2/08 12:00 AM 7/2/08 12:00 PM 7/3/08 12:00 AMPh

ase

Cur

rent

(A)

Phase RPhase SPhase T

24

Steady State Operation (II)Steady State Operation (II)

12.0

12.5

13.0

13.5

14.0

14.5

15.0

7/2/08 12:00 AM 7/2/08 12:00 PM 7/3/08 12:00 AM

LN2

Pres

sure

(bar

a)100

200

300

400

500

600

700

LN2

Mas

s Fl

ow R

ate

(g/s

)

Inlet Pressure

Return Pressure

Flow Rate

66

67

68

69

70

71

72

73

7/2/08 12:00 AM 7/2/08 12:00 PM 7/3/08 12:00 AM

Tem

pera

ture

(K)

Inlet Temperature

Return Temperature

25

Sound IssuesSound Issues

• Several questions regarding noise at the site (during operation)

• Conducted sound study- 35 db at ambient

- Source: refrigerator building

- 50 db with refrigerator running

• Acoustical Louvers- Lowered sound signature

during operation to 38 db (modeled)

26

Sound & Site MitigationSound & Site Mitigation

27

LIPA 2LIPA 2

Transmission Voltage Cable ProjectLong Island Power Authority

New York


28

LIPA 2 Project TeamLIPA 2 Project Team

29

Major Challenges of LIPA II ProjectMajor Challenges of LIPA II Project

• System Design- Integrate single phase fault current limiting phase into the existing

system

• 2G HTS Conductor Design- Address real-world cabling stress using standard manufacturing

equipment

• Cable Design- Demonstrate field joint- Demonstrate field reparable cryostat

• Develop a 20 KW modular high efficiency refrigerator

30

LIPA II HTS Cable SystemLIPA II HTS Cable System

Existing HV Termination

RedundantCooling & Control

Existing Cold Termination

Bul

k LN

2S

tora

ge

Heat

Pow

er

SC

AD

A

Supply

Return

Replacement 2G Phase

Field Joint

31

LIPA 2 HTS Cable ConceptLIPA 2 HTS Cable Concept

Copper Shield Stabilization to be removed

HTS-Shield

High Voltage Dielectric

Cable conductor has to be redesigned for thermal contraction (and current limiting)

Inner Cryostat Wall

Outer Cryostat Wall

LN2 Coolant

32

LIPA 2 WireLIPA 2 Wire

• YBCO Coated Tapes- Lower Tc, higher resistance substrate: Can be made to

be current-limiting- Different dimensions and physical properties:

• YBCO coated onto one side of buffered Ni-W substrate

• Brass laminated onto both sides• ~ 0.3 mm thick, splices even thicker

• Splices are being developed

33

Cable design and manufacturing processCable design and manufacturing process

• Dummy cable approach to develop the cable design

- Develop cable design based on modified modeling tools

- Manufacturing of short samples • Measurement of electrical

characteristics (AC-loss)- Manufacturing trials using industrial

machine adapted to HTS tape stranding- Testing of samples in terms of mechanical

and high voltage aspects

• Status- Two different design options considered- First manufacturing trials (dummy cables)

focus on one of the two designs

34

Dummy cable 01 Dummy cable 01 -- Current StatusCurrent Status

• Hollow flexible former- Dummy cable is being produced now- Superior concept

• Only small force due to thermal contraction• Small cross-section, stainless steel:

• High resistance, good for current limitation - Requires some effort due to flexibility of former in the

machine- Preferred design

35

High Voltage TerminationHigh Voltage Termination

• LIPA 1 terminations design is kept for this project but adapted for the new YBCO HTS cable:

- Removal of the cable termination shrinkage management (blocking of the cable)

- Adaptation of the cable connection for 2G wires

• Status:- Updating of the cable connection is in progress with different new brazing alloys

studied- Continuation of the development required now some LIPA 2 cable samples in order

to achieved some connection and mechanical tests and improved the components

36

High Voltage TerminationHigh Voltage Termination

• LIPA 1 terminations design is kept for this project but adapted for the new YBCO HTS cable:

- Removal of the cable termination shrinkage management (blocking of the cable)

- Adaptation of the cable connection for 2G wires

• Status:- Updating of the cable connection is in progress with different new brazing alloys

studied- Continuation of the development required now some LIPA 2 cable samples in order

to achieved some connection and mechanical tests and improved the components

37

Superconducting Cable JointSuperconducting Cable Joint

• HTS cable joint- Develop and test a straight joint to connect

superconducting cables• Design of conductor connection• Design of joint dielectric insulation• Design of screen connection• Design of joint cryostat

• Cryostat for subscale test• Cryostat for on site installation

- Full prototype test of cable joint in the laboratory- Installation of a single cable joint on site

38

Status: High Voltage JointStatus: High Voltage Joint

• A first joint design has been set up considering two main physical constraints- Thermal: no overheating in the central cable connection with nominal current (not in

direct contact with liquid nitrogen)

- Electrical: E field management in an optimum dimension of the joint

• Prototypes for testing assembly procedures successfully prepared and tested with nominal current in LN2 (temperature measurement)

39

Status: High Voltage JointStatus: High Voltage Joint

• The first design of the joint has been assembled in NEXANS Hanover testing laboratory in June/July 2008

• First results on this component achieved in September 2008• AC withstand test 190 kV / 30 min• Lightning impulse test 650 kV (+/-)• Partial discharge measurement

40

Inlet Termination(Connection to the Transformer)

Outlet Termination with the Joint inside

25 m Coated Conductor Cable

Joint in the Test FieldJoint in the Test Field

41

Field Repairable CryostatField Repairable Cryostat

• Field repairable cryostat- Perform optimization study to determine

cryostat vacuum barrier distance based on - Develop and demonstrate vacuum barrier

manufacturing techniques- Develop improved thermal insulation system to

perform under repair vacuum conditions- Demonstrate field repair in laboratory

• Status of work- Vacuum barrier manufacturing techniques

• Various designs developed- Improved thermal insulation system

• Investigation of vacuuming behavior of alternative thermal insulation materials

42

Modular Refrigeration System ObjectiveModular Refrigeration System Objective

Develop a new Refrigeration technology dedicated to long-length HTS cable with the main characteristics below

- Low operation cost• High efficiency

• Low maintenance

- Low refrigerator cost• Simple design

• Modular design

- High reliability

- Long lifetime

43

Refrigeration System ObjectiveRefrigeration System Objective

Develop a new Refrigeration technology dedicated to long-length HTS cable with the main characteristics below

• Liquid nitrogen delivered 72 K

• LN2 pressure drop 3 bars

• Cold power 120 kW total - 20 kW Modules

• Efficiency > 20% Carnot

• Cooling Air cooling (-20 / 50°C)

• Manufacturing cost target <$100/cold W series production

44

Refrigerator Development Status (Phase 1)Refrigerator Development Status (Phase 1)

Progress made thus far- Thermodynamic analyses of reverse Turbo-Brayton cycle Completed

- Cooler configuration scenarios Identified

- Numeric modeling of cooler configuration and

Refrigeration sub components Completed

- Model validation Completed

- Creation of a numerical model for each cooler configuration Completed

- Optimization of each cooler configuration Underway

45

Project HydraProject Hydra

Distribution Voltage Cable ProjectConsolidated Edison

New York City


46

Team Roles and ResponsibilitiesTeam Roles and Responsibilities

SouthwireAMSC

Cable and Accessory Design

Cable Manufacturing

Cable and Accessory Installation

Utility Requirements

Project Oversight

HTS FCL Cable System Site

System Hardware Development

Wire Development

Wire Manufacturing

Project Management

Technical Oversight

System Design

AMSCPrime Contractor

DHSS&T Division

ORNL

Con Edison

Technical Support

50m Prototype Cable Test Site

Air Liquide

Altran Solutions

47

Installation SiteInstallation Site

World’s First FCL Distribution Cable to be Installed in Operating Grid

48

Program StructureProgram Structure

Phase 1System

Development

Phase 1AFault Current Limiting

Cable technology

Phase 1BStand-Alone Fault Current

Limiting Technology

Phase 2System Installation

ORNL50 Meter Test and Technical Support

DHS/ HYDRACurrently ExecutingPlanning

49

HYDRA HTS Cable SystemHYDRA HTS Cable System

Supply

Return Refrigerator

PowerHeat

HTS Cable

Return Line

50

138kV Transmission Bus

13.8kV Distribution Bus

Substation #1138kV Transmission Bus

13.8kV Distribution Bus

Substation #2

HTS Fault-Current Limiting CableFast Switch

(Circuit Breaker)

Reactor Conventional Copper Cable

To Loads To Loads

Secure Super GridsSecure Super Grids™™ TechnologyTechnology

Note: Red breakers are ClosedGreen breaker is Open

51

Cable DesignCable Design-- TriaxTriaxTMTM by by SouthwireSouthwire

HTS LayersHTS Layers

Hollow FormerHollow Former

DielectricDielectric

CryostatCryostat

ShieldShield

52

3 m Cable FCL Tests3 m Cable FCL Tests

• The prospective fault current of 60 kA was reduced to 44 kA on the first ½ cycle to < 30 kA at the end of the 140 ms duration fault

• A perspective 140 ms fault current of 44 kA was reduced to 29 kA

• The voltage developed due to the heating was 8-11 V/m over the 140 ms duration fault

• This was comparable to the design fault of 300-m cable which results in ~ 10 V/m

• Measured temperature increase to 85-95 K

• Re-cooling time to 77 K is 9 min

• No change in temperature measured after a 9.1kA, 270ms through fault test

• No change in temperature or voltage after a 2000 ms, 7.2kA overload test (1.8X)

53

3m Cable FCL Tests3m Cable FCL Tests

54

3 m Cable FCL Tests3 m Cable FCL Tests

55

Refrigerator RequirementsRefrigerator Requirements

• Refrigeration Cycle chosen is the Reverse-Brayton- Best suited technology for high power applications (> 6 kW)- Best return on specific efficiency (We/Wc) vs. capital cost

• Flexibility Requirement:- 80% of time at 50% heat load on HTS cable

• Reliability - Redundancy accomplished at component level: compressors,

pumps, expanders, electronics, instrumentation- No 1st order single point of failure allowed

• Capacity Margin- Current design has 50% safety margin to the expected losses

56

Reverse BraytonReverse Brayton--Cycle HardwareCycle Hardware

- Estimated foot print size & weight• 13 m x 7 m ( 42’ x 25’ ) + roof for cooling water exchanger• ~ 24 000 kg ( 53 000 lbs ) empty• Fits within available space

57

FCL ProjectFCL Project

Transmission Voltage FCL ProjectSouthern California Edison

California


58

Team Roles and ResponsibilitiesTeam Roles and Responsibilities

SiemensAMSC

FCL Module and Accessory Design

FCL Manufacturing

FCL Module and Accessory Installation

Utility Requirements

Project Oversight

HTS FCLSystem Site

System Hardware Development

Wire Development

Wire Manufacturing

Project Management

Technical Oversight

System Design

AMSCPrime Contractor

DOE

SPE - SCE

SCE

Air Liquide

Nexans

HV Termination

HV Consulting

59

SuperLimiterSuperLimiterTMTM Demonstration SiteDemonstration Site

The Valley Substation is selected

• Selection criteria- Voltage- Transmission planning- Civil engineering

• Valley Substation selected

• Located near Riverside, CA in a desert climate

• Analysis used to select bus tie application

• Significant load growth planned over the next 10 years

- Tapped external reactor enables device to easily adapt

RiversideRiverside

Valley Valley SubstationSubstation

60

SCE ProfileSCE Profile

•• 50,000 Mile50,000 Mile22 Service TerritoryService Territory

•• 120 years of service120 years of service

•• $17 Billion T&D Assets$17 Billion T&D Assets Distribution•• 85,000 Circuit Miles85,000 Circuit Miles•• 690,000 Transformers690,000 Transformers

Customers•• 4.7 Million Meters4.7 Million Meters•• 13 Million 13 Million

CustomersCustomers•• 22,889 MW Load22,889 MW Load

Transmission•• 12,600 Circuit Miles12,600 Circuit Miles•• 4,200 Transformers4,200 Transformers

SCE is one of the largest utilities in the United States

61

SuperLimiterSuperLimiterTMTM Southern California EdisonSouthern California Edison• SCE is investing in the future

- > $3 billion invested in T&D over the last five years- $11 billion planned infrastructure investments over the

next decade.• SCE has considerable experience with

superconducting Fault Current Limiters- Since 1993 in DOE-SPI, tested a 15kV FCL in 1999- SCE role in this program is

• Specifying requirements • Providing the prototype operation site

• 138 kV Transmission Voltage level FCL addresses - Elimination of CB and other equip. replacement- Enhanced reliability, shorter customer outages- More stable, higher-quality electricity supply- A “self-healing” grid July 1999: FCL at a Southern California

Edison substation

SCE has unique experience with HTS FCL technology and this program extends this to transmission voltage levels

62

SuperLimiterSuperLimiterTMTM Major ElementsMajor Elements

InsulationInsulationStainless StripStainless StripHTS FilmHTS FilmNiW StripNiW StripSolderSolder

1.2 cm insulated HTS tape 1.2 cm insulated HTS tape based on standard insertbased on standard insert

Cryostat sized for Cryostat sized for modular expansionmodular expansion

Design based on validated components is designed for modular expansion

Cooling System Similar Cooling System Similar to Navy Motor Programto Navy Motor ProgramN+1 RedundancyN+1 Redundancy Bifilar 2.2 MVA medium voltage Bifilar 2.2 MVA medium voltage

module tested Jan. 2007module tested Jan. 2007

Valley Valley SubstationSubstation

138kV termination in 138kV termination in operation at LIPA siteoperation at LIPA site

63

FCL Operating PrincipleFCL Operating Principle

FCL system operation is based on simple operating principles

Reactor

Normal State Resistance

Virtual SwitchSuperconductor

Physical Switch

Supply Bus

Load Bus

Under normal conditions, power flows through superconductor with virtually no impedance and system is electrically “invisible”

During fault conditions, superconductor becomes resistive and with reactor, limits current

Physical switch opens

to protect FCL system;

reactor maintains

current

Shortly after fault clears, power resumes flow through superconductor

64

Basic SpecificationsBasic Specifications

As required by customer

1.6puTrip Current

As required by customer

40kASite Limited Current

>80kA63kAMaximum Site Unlimited Fault Current

>2,000A1,200ANominal Current

138kV138kVInsulation Class

115-138kV115kV rmsNominal Voltage

Production Units

Prototype System

Requirement

Team has approved a working specification for system

Refrigeration System

Power Heat

FCL Vessel Assembly

Protection and DAQ System

ReactorSized to Limiting Requirements

Opening Switch

Source

Load

SwitchControl

65

SuperLimiterSuperLimiterTMTM Operating ConditionsOperating Conditions

•Constraints-No bubbles around the bottom of bushing – sub-cooled LN2-Termination dielectric requirement P > 3bar-Fast recovery time – saturated LN2

•Solution-Operate FCL in sub-cooled LN2 with nominal operating temperature lower than design point.• FCL design at temperature 74K@5bar(a), but operate at temperature 72K@5bara

• Temperature margin determines the number of faults the system can absorb before system is off-line to re-cool

• 2K margin allows LN2 to absorb 57MJ energy (~6 faults)• 5 bar pressure will allow LN2 in coil vicinity absorb fault energy without bubbling

FCL operates at high pressure sub-cooled LN2 temperature

Refrigeration System

Power Heat

FCL Vessel Assembly

66

SuperLimiterSuperLimiterTMTM Refrigeration SystemRefrigeration System

Pressure

Level

Level

6000Planned Capacity4250Total Max. Predicted1950AC Losses

350Lines, Valves, Bayonets

900Terminations

200Other Refrig. System

850Cryostat

Value (W)Heat Load

• AMSC has operated HTS systems in utility/harsh industrial conditions- LIPA and TVA/SuperVAR Project

• DOE-FCL system based on lessons learned in those systems- Phase 1b – open cycle option shown above- Phase 2 - replace with closed cycle modification

• Simplified, COTS based system• Significant margin planned for prototype system

Refrigeration based on experience at LIPA and other AMSC utility HTS systems

67

SuperLimiterSuperLimiterTMTM Test SiteTest Site

Bus TieBus Tie115 KV 115 KV Outgoing Outgoing FeederFeeder

1000 MW 1000 MW Future GenFuture Gen

Inland EmpireInland Empire

115 kV115 kV

115 kV115 kV

500 kV500 kV

115 kV115 kV

“A”“A” “B”“B”

“C”“C” “AB”“AB”

SerranoSerrano500 kV500 kV

Devers Devers 500 kV500 kV

(Studied)(Studied)(Selected)(Selected)

A bus tie application at the Valley Substation is selected

Present Installation:• 4-3Phase, 336/448/560 MVA

525-120 kV, OA/FOA/FOA Transformers.

• Sectionalized 115 kV bus -each section fed by 2 transformers

• Max. single-phase-to-ground fault = 30 kA

• All 115 kV CBs rated 40 kAPlanned Future Installation:• Load growth in the area and

interconnection of new generators will require additional transformers

• Fault current duty will rise above 40 kA

68

SwitchingSwitching Module Module forfor thethe HV SFCL ProjectHV SFCL Project

Main design characteristics• The switching module comprises

3 parallel x 17 series = 51 bifilar pancake coils per phase

• Two in hand winding with 12 mm wide wire to increase the current

• Improved electrical strength due to:- Insulated wire- New contact design- Corona rings around the coils

• Horizontal stack with radial supports between module and cryostat wall

Regions stressed by BIL tests, numbering see next slide

Alternating current directions between adjacent turns of bifilar coils cancel most magnetic fields

(1)(1)

(1)(1) (2)(2)

(3)(3)

69

Performance Modeling and TestingPerformance Modeling and Testing

Switching• First tests on a 3 m sample of 12 mm wide HTS-wire:

Critical current 167 A @ 77 K, 258 A @ 72 K

• More than 60 switching test in saturated (77 K) and sub-cooled (72 K, 1.2 bar) LN2

0 10 20 30 40 50-2000

-1000

0

1000

2000

-400

-200

0

200

400

Time (ms)

Cur

rent

(A)

Volta

ge (V

)

T: ~72 K

77 K, 77 K, satsat., t: 100 ms., t: 100 ms

72 K, 1.2 bar, t: 500 ms72 K, 1.2 bar, t: 500 ms

70

Performance Modeling and TestingPerformance Modeling and Testing

Recovery time• About 12 - 15 sec measured on full size dummy coil in sub-cooled LN2

• 12 mm wide dummy wire insulated with wrapped Teflon tape• Amount of LN2 available for cooling restricted by appropriate enclosure

to simulate adjacent coils

-0.05 10 2060

70

80

90

100

110

0

T: 77 K, p: 1 bar T: 72 K, p: 1.2 bar

Res

ista

nce

ratio

(%)

Time (s)

71

FCL FCL TerminationTermination Design ValidationDesign Validation• AC withstand test successfully completed according IEC 60840

- 190kV / 30 minutes

• Partial Discharge measurement sucessfully completed (IEC 60840)- Voltage increase up to 140 kV for few minutes- Decreasing to 114 kV and measurement- No PD measured (noise level < 3pC)

• Lightning impulse test successfully completed (IEC 60840)- 650 kVp (10 shots in both polarity)

• Switching impulse successfully completed based on IEEE C57.12.00:- Success of the test (540 kVp 250/2500µs – both polarity)

FCL termination high voltage design successfully validated

72

SummarySummary

• AMSC is currently advancing the state of the art in HTS power products

- Worlds First Transmission Voltage HTS Cable in Operation

- Worlds First Fault Current Limiting Cable for use in a distribution grid under development

- Transmission Voltage Fault Current Limiter under development

superior performance.powerful technology.

SuperPower, Inc. is a subsidiary of Royal Philips Electronics N.V.

Transmission Level HTS Fault Current Limiter

Chuck Weber

8th Annual EPRI Superconductivity ConferenceOak Ridge, TN November 12, 2008

8th Annual EPRI Superconductivity Conference – November 12, 2008

SFCL program overview

15.248"

7.362"

15.248"

7.362"

138 kV, 650 kV BIL Bushings

Vacuum Vessel

Pressure Vessel

Matrix Assembly

Inner diameter

Inner Height

HTS Assembly Height

Assembly diameter

Partners

Specifications• YBCO based, resistive type FCL• 138 kV class device• Fault Current – 13.8 kA• Load Current – 1,200 Arms• Design fault current – 37 kA• Design device response – Recover

to superconducting state after a fault carrying full load current


Generalized SFCL Specification Development

• Baseline Design for Program was the AEP SPORN substation site– This is a niche application site, operating at 400Arms, 138 kV– Prospective fault current 26 kArms (~90 kA peak) and 13.8 kArms

(~ 37 kA peak)

• Working with AEP, we have identified a site with broader generalapplication

– TIDD substation– 1,200 Arms, 138 kV– Prospective fault current is 13.8 kArms (~37 kApeak)


TIDD Substation – (Partial) One-Line Diagram

Proposed SFCL Installation Location


Prior accomplishments

• Proof-of-Concept demonstrated– MCP 2212 (2004)– 2G YBCO (2006)

• Beta device testing specifications established

• Completed design and testing of HV bushings (SEI)

• Investigated several ‘engineered’ 2G architectures for improved RUL

• Design and laboratory testing of shunt coils to withstand high fault transient loads

• Thermal simulation of RUL process• Weibull plots of ‘standard’ 2G failures• Conceptual CRS & vessel design• Investigated LN2 dielectric properties

2G FCL - Probability of failure for 2G tapes as function of energy input

0.01

0.1

1

10

100

20 25 30 35 40 45 50

Energy [J/cm/tape]

Prob

abilit

y of

failu

re [%

]

Probability of Failure - Test dataProbability of Failure Calculated using Weibull Distributuon


Improvements to shunt coil and contact design

• Shunt coil improvements:– Manufacturing improvements

(easier assembly, more robust coil)

– Mechanical strength – Multi-Layer winding (size

reduction)• Connector improvements:

– Shape optimization to avoid contact hotspots

– Improvement in RUL Time– Improvement in RUL Current– Improvement in consistency of

contact resistance


Tape heating near contact during fault impacts RUL


Correlation between different contact geometries

Total Current (80A peak)

Recovery Voltage

Superconductor’s Current

Straight Thick Contacts(M3-460 Tape):I load = 80 A

RUL = 82 sec.


Recovery Voltage



Recovery Voltage


Straight α-Tapered Contacts(M3-460 Tape):

I load = 80 A RUL = 3.5 sec.

Straight β-Tapered Contacts(M3-460 Tape):

I load = 80 A RUL = 2.8 sec.


Recent KEMA tests• Recent rounds of KEMA testing focused on critical AEP reclosure sequence on

an HTS element

• Straight elements were used

• Improved connector designs were used

• “Standard”, pre-qualified tapes were used

• Test Dates: May 2008, July 2008

5 CyclesFault

13kA/7kA

18 Cycles Load Current

15 sec Load Current

135 sec Load Current

5 CyclesFault

13kA/7kA

5 CyclesFault

13kA/7kA

5 CyclesFault

13kA/7kA

Breaker opens and locks-out

Recovery under NO Load Current

5 CyclesFault

13kA/7kA

160 sec Load Current


2G RUL capabilities tested at KEMA

• ‘Standard’ SF12100 2G wire used

• Test conditions- 37 kA fault

- follows AEP sequence

• Test variables- Shunt impedance

- Number of parallel tapes

- System voltage (v/cm/tape)

- Load Current

16 Tapes8 Tapes

4 Tapes100V

200V

250V

300V

0

50000

100000

150000

200000

250000

Load Pow er (VA)

Total Recovered Power, 2x5 cycles Faults at 37kA with 10 mOhm

Parallel Tapes

Voltag

e


3 x Base-Line Voltage

w/o Load

w/ Load

Achieving RUL is a difficult task

Without load current recovery is very fast

Adding load current makes recovery much more difficult


Base-Line Voltage

RUL

1.5 x Base-Line Voltage

RUL

3 x Base-Line Voltage

RUL

Electrical stress on the tapes can limit RUL

• RUL time can affected by increasing the V/cm on the tape

• Limits of the design optimization are understood


Factors impacting RUL defined by test results

1.67 m-Ohm

5 m-Ohm

100 V200 V

250 V300 V

0

10000

20000

30000

40000

50000

60000

70000

80000

Load Power (VA))

Total Recovered Power, 2x5 cycles Faults at 37kA with 4 Tapes

Shunt ImpedanceVoltage

Sample surface plot of RUL conditions


Ability to predict RUL over wide design space

1.67

m-O

hm

5 m

-Ohm

4Tap

es, 1

00V

4Tap

es, 2

50V

8Tap

es, 1

00V

8Tap

es, 2

50V

16Ta

pes,

100

V

16Ta

pes,

250

V

0100200300

400500

600

700

800

900

1000

Maximun Recovered Load Current

Recovered Current with 2 Asymmetrical 37kA Faults, 5 cycles each

ImpedanceVoltage, #Tapes

Maximum Load Current as a function of shunt impedance, operating voltage & number of tapes


RUL with 90% of the Power recovered within the 2nd and the 3rd 37 kA Faults

Worst case conditions at Tidd can achieve RUL

Full recovery expected with optimal bath conditions


Bath Conditions Impact on Ability to Recover

100 150 200 250 300 350 400 450 500 5500

100

200

300

400

500

600Heat OutHeat In

No Recovery Due to Film Boiling

Temperature (K)

Pow

er (W

)

Lowering the shunt coil value or increasing the resistance of the stabilizer layer will help with film boiling.

Lower Zshunt, Higher Ztape

Boiling Heat Transfer for LN2

0.1

1.0

10.0

100.0

1.0 10.0 100.0 1000.0

Twall - Tsat (K)

q/A

(W/c

m2 )

During the fault transient, tape heats up to film boiling region. Bath conditions (pressure, subcooling) shift boiling heat transfer curveBath conditions have an impact on the dielectric strength of LN2


Bath Conditions Impact on Ability to Recover

Boiling Heat Transfer for LN2

0.1

1.0

10.0

100.0

1.0 10.0 100.0 1000.0

Twall - Tsat (K)

q/A

(W/c

m2 )

Once film boiling threshold is crossed, nucleate boiling ensues Bath conditions (pressure, subcooling) shift boiling heat transfer curveBath pressure shifts saturated boiling temperature, limiting nucleate boiling recovery

75 80 85 90 95 1000

100

200

300

400

500

600Heat OutHeat In

No Recovery Due to Nucleate Boiling

Temperature (K)

Pow

er (W

)

Lowering the operating pressure will help with nucleate boiling, but decreases dielectric properties

Lower pressure


Modeling indicates where operating conditions for successful RUL exist

Recovery Under Load vs Number of Tapes

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

0 2 4 6 8 10 12 14 16

Number of Tapes per Element

Rec

over

y Lo

ad C

urre

nt (a

rms)

Baseline

Pressure = 0.5 atmTbulk = 71.922 K

Pressure = 0.5 atmTbulk = 71.922 KStabilizer = 1% AgAu

Pressure = 0.75 atmStabilizer = 1% AgAu

Pressure = 0.75 atmStabilizer = 2.2% AgAu

Baseline Shunt = 5 mΩ/m

Baseline Shunt = 7.5 mΩ/m

Baseline - Substrate = 4 mil Stabilizer = Ag Shunt Coil = 10 mΩ/m No dielectric coating Ic @ 77 K = 250 amps n-value = 20 Pressure = 1 atm Tbulk = 72 K

19 Managed by UT-Battellefor the Department of Energy DOE Peer Review 2008

Introducing bubbles in LN lowers breakdown strength: FCL recovery

• Two experiments– Open bath LN– Pressurized cryostat

• Nitrogen gas provided by fused silica capillary tube

• Varied flow rates• Parallel plane profiled

SS electrodes• BD strength of LN is

~5x the gas at 1 bar

Bubbles form thermally or electrically and can affect the breakdown strength

2 mm gap0.5 mm capillary tube

Important for FCL Recovery under Load

20 Managed by UT-Battellefor the Department of Energy DOE Peer Review 2008

Effect of externally provided bubbles on LN Breakdown: AC breakdown

all data w and w/o bubbles

Breakdown Field (kVrms/mm)5 6 7 8 9 20 3010

Cum

ulat

ive

Failu

re P

roba

bilit

y (%

)1.0

5.0

10.0

20.030.040.050.060.070.080.090.095.099.099.9

Effect of Bubbles

Presence of bubbleswithout bubbles with bubbles

Aver

age

Elec

tric

Fiel

d (k

Vrm

s/m

m)

0

2

4

6

8

10

12

14

16

18

Liquid nitrogen at 1 bar

• Bubbles in LN lowers breakdown strength• Change in slope at lower probability indicates change in BD mechanism


Summary

• Significant progress in understanding and impacts of:– RUL

• Variables impacting RUL studied and understood• Worst case conditions at TIDD can be met• Impact of device design and cost under evaluation

– LN2 Dielectrics• Impact of bubbles on breakdown mechanism and dielectric

strength

• Loss of cryogenic partner a setback, but not fatal• Next step: Alpha detailed design


Thank You for your attention!

For more information:

www.superpower-inc.comor

[email protected]



Status Update for the Albany HTS Cable ProjectC.S. Weber (SuperPower)

8th Annual EPRI Superconductivity ConferenceOak Ridge, TN November 12, 2008


Program Overview– 350m long - 34.5kV - 800Arms - 48MVA– Cold dielectric, 3 phases-in-1 cryostat, stranded copper core design– Two Phases – Phase I - 320m + 30m BSCCO

– Phase II - 30m BSCCO replaced by 30m YBCO cable

Supported by Federal (DOE) and NY State (NYSERDA) Funds

Design, construct and operate the Cryogenic Refrigeration System, and provide overall cable remote monitoring and utility interface

Design, build, install, and test the HTS cable, terminations, & joint

Host utility, conventional cable & system protection, system impact studies

Project Manager; Site infrastructure, Manufacture of 2G HTS wire


Site Location

Phase II: 30m YBCO

Phase I: BSCCO


System Protection Philosophy

• Worst case fault conditions – 23 kA rms (33 kA peak)• Multiple levels of relay & breaker protection

– Primary - RFL-9300 charge comparison relays (87L) – 8 cycle clearing time– Secondary - SEL-311B relay packages – 8 – 38 cycle clearing time

• Breaker failure protection– Will initiate fault clearing by tripping breakers on associated Menands or Riverside 34.5kV bus– cleared in 20 to 50 cycles (0.33 to 0.83 sec)

• System monitoring @– BOC Remote Operating Center– NM Eastern Regional Control Center


Advantages of the 3-in-One CableDesign

• Compact size (O.D. = 135mm) (5.3”)

• Nearly perfect magnetic shielding

– > 95% cancellation of field

• Significant reduction of contraction forces due to ‘slack’ winding

• Excellent fault current protection

– Cable remains superconducting at worst case fault condition, survives extended duration (2nd

contingency) fault without damage

Albany HTS Cable Design

HTS Conductor（ 2-layer）

HTS Shield（ 1-layer）

Cu Shield

135 mm35 mm

Electrical Insulation（ PPLP +Liquid Nitrigen）

Cu Stranded Former

Tension Member

Stainless Steel Double Corrugated

Cryostat

HTS Conductor（ 2-layer）

HTS Shield（ 1-layer）

Cu Shield

135 mm35 mm

Electrical Insulation（ PPLP +Liquid Nitrigen）

Cu Stranded Former

Tension Member

Stainless Steel Double Corrugated

Cryostat


Cryogenic Refrigeration System: Approach

Cryocooler

Thermosyphon

Liquid NitrogenStorage/buffer

Subcooled liquid nitrogen loop

HTS cable

Hybrid arrangement permits transparent use of bulk liquid nitrogen for back-up

Thermosyphon provides common heat exchange interface between cable and open or closed refrigeration sources

Advantages:- excellent reliability/cost ratio- compact footprint- flexible ‘plug & play’ design- good efficiency


Minimum CRS Requirements & Cold Box Arrangement

1.4 m

1.6 m

BOC

Item Specification

Coolant supply temperature 67 to 77 KTemperature stability +-0.1 K - normal operation

+-1.0 K - backup operationRefrigeration capacity 5 kW at 77 K

3.7 kW at 70 KMinimum coolant pressure 1 to 5 barg +-0.2Maximum coolant flow rate 50 liter/min +-1

(excluding CRS)


Post-Cable Testing: Cryogenic System Step Response

60

62

64

66

68

70

72

74

76

78

80

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Time (hours)

Tem

pera

ture

(K)

0

5

10

15

20

25

30

Coo

ling

Pow

er (K

w)

Coolant return

North Termination

South Termination

Coolant Supply

Refrigeration power

Hybrid operation

3 Kw nominal

8 Kw peak

+ - 0.05K

+ - 0.10K

Pre-energization: 3 Kw nominal. Post-energization: 3.1-3.3 kW nominal overall heat load


66

67

68

69

70

71

7/20 8/17 9/14 10/12 11/9 12/7 1/4 2/1 3/1 3/29 4/26

Date (2006-2007)

Tem

pera

ture

[K]

0

4

8

12

16

20

Tran

smitt

ed E

lect

ricity

[MVA

]

Cable Inlet Temperature

Cable Outlet Temperature

Transmitted Electricity

Chiller System ShutdownSupply Voltage Issue

Energizedon July 20,2006

Completedon May 1, 2007

Fault Current Event

7kA

8 cycle

The HTS cable system was checked for damage after the fault eventNo Issues Re-connected to Power Grid

More Than 6,700 Hrs of Reliable Power Transmission

Summary of Phase I Operation


-200

-150

-100

-50

0

50

0 100 200 300 400 500 600 700 800Position [m]

Tem

pera

ture

[ ]

30m HTS Cable320m HTS Cable

350m Return Pipe

12H

1D

3D

5D

7D

9D

11D

14D

21D

SouthTerm

NorthTerm

Before warming-up,• Megger Test• Ic Measurements

Warm-up Process,(1) LN2 pumped into the CRS bulk storage tank(2) Remaining LN2 in system allowed to evaporate naturally

No Change

Vacuum level• No leakage

Cable Tension• Returned to theoriginal value

(approx. 200kgcompressive force)

Commencement of Phase II


1 Meter Cable Characterization (after removal)

-50

0

50

100

150

200

0 200 400 600 800 1000 1200

I(Amperes)

V(uVolts)

Contact #2 R=32 uohms

Contact #1R = 6 uOhms

0

10000

20000

30000

40000

0 500 1000I(Amperes)

V(uV)

Contact resistance measurements were performed in the superconducting state T=75.5K

• The critical current of the inner layer with 12 strands of superconductor was measured at 75.5K in self field.

• Distance between voltage taps = ~75cm• Ic = 965Amperes @ 1μV/m• 1100A @ 1μV/cm

• Contact was made to 12 strands with single strand Ic(B=sf, 75K) ~ 92 amperes

*Data courtesy of Yates Coulter, LANL


2G wire cable winding

3 core stranding

In 2007, 30 m cable was manufactured by Sumitomo Electric with ~10,000 m of SuperPower 2G HTS wire

Cu StrandedWire Former

Electric Insulation(PPLP + Liquid Nitrogen)

Stainless Steel DoubleCorrugated Cryostat

Cu Shield2G HTS wire(2 shield Layers)

2G HTS wire(3 conductor Layers)

135 mm


Summary of 30 meter YBCO Cable Shipping Tests

• Manufacture of 30m YBCO cable completed in March 2007

Critical Current•　Conductor : 2660 – 2820A (DC) at 77K• Shield : 2400 – 2500A (DC) at 77K

AC Loss• 0.34W/m/phase at 0.8kArms, 60Hz

Bending Test (18D: Bending Dia. = 2.4 m)• No Ic degradation• No defect was found at dismantling

Inspection

Voltage tests (Based on AEIC)AC 69kV for 10 minute,

　Imp ±200kV, 10 shots/eachDC 100kV for 5 minutes

The following shipping tests were conducted successfully on samples from long cable:


-0.5

0

0.5

1

1.5

2

0 500 1000 1500 2000 2500 3000Current (A, DC)

Elec

trica

l Fie

ld(u

V/cm

)

Core-1Core-2Core-3

Ic Criterion (1uV/cm)

-0.5

0

0.5

1

1.5

2

0 500 1000 1500 2000 2500 3000Current (A, DC)

Elec

trica

l Fie

ld(u

V/cm

)

Core-1Core-2Core-3

Ic Criterion (1uV/cm)

Sample: 3 meter 3-Core • Ic (Conductor) = Approx. 2660 – 2820A (DC, 77K, 1uV/cm)• Ic (Shield) = Approx. 2400 – 2500A (DC, 77K, 1uV/cm)

Conductor Shield

Very good match between test results and design values

YBCO Cable - Critical Current Measurement


0.001

0.01

0.1

1

100 1000 10000Loading Current (Arms, 60Hz)

AC

loss

(W/m

/pha

se)

Measured value

Sample : 2.5 meter single coreCurrent loading : go & return through conductor and shieldMeasuring : Lock-in amplifier with electrical 4 terminals

0.34 W/m/ph @ 800 ArmsSlightly better result than the

1 meter test sample core

AC Loss Measurement


Fault Current Test with 1 m 2G Sample CableFault Current Testing• Sample: BSCCO Core – YBCO Core

(Compare YBCO core with BSCCO one)• Current: 23kA• Duration: 8 – 38cycles• Cooling: Open Bath (77K)

Test Site : Nissin Electric (Kyoto)

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50Duration [cycles, 60Hz]

Max

imum

Tem

pera

ture

Ris

e [K

]

BSCCO ConductorBSCCO ShieldYBCO ConductorYBCO Shield

Shield

Conductor

Generator(5000V)

Lg

L1 L2 L0Transformer(6600V/550V)

Test SamplesSWGenerator(5000V)

Lg

L1 L2 L0Transformer(6600V/550V)

Test SamplesSW

Temperature Rise During Faultnearly identical to BSCCO core


Replacement of 30 meter section with new YBCO cable[ 30m cable Installation ]

[ Joint Re-assemble（BSCCO-YBCO）]

[ Termination Re-assemble ]

World first’s HTS cable replacement is completed!


Summary of Various Commissioning Tests at Phase-II

100 kV, 5 minutes, each phase (based on AEIC) : good

350 m cable section (including joint): 1.0kWEntire cable system (not including CRS: 3.4kW

2.3kA (at 73K), 2.8kA (at 69K): Same Ic as Phase-I

Maximum core tension: approx. 1000kgTension minimized by “loosely stranded 3-core structure”

Vacuum level at each part: good (no leakage)Core behavior inside the joint: within the scope of Design

0.61 MPaG (based on ASME code): good

Test Results

DC withstand voltage test

Heat loss measurement(under no-load condition)

Ic measurement (dc, defined at 1uV/cm)

Initial cooling test

System withstand pressure Test

Test Items

HTS cable system successfully passed following commissioning tests:

-0.5

0

0.5

1

1.5

2

2.5

0 500 1000 1500 2000 2500 3000Current [A, DC]

Elec

tric

Fiel

d [u

V/cm

]Core-1

Core-2

Core-3

Ic critrion (1μV/cm)

Cable Mean Temp : 73K 69K

-200

-150

-100

-50

0

50

0 50 100 150 200 250 300 350 400

Length [m]

Tem

pera

ture

[]

SouthTermination

6H10H

18H1D 1.5D

10.5D11.5D

3D

9D

10.7D 10.8D 10.9D

0H

NorthTermination

0 50 100 150 200 250 300 350


Demonstration of the world’s first device with 2G HTS wire in a live power grid

0

0.2

0.4

0.6

0.8

1

1.2

1/7 1/21 2/4 2/18 3/3 3/17 3/31

Date (2008)

Tem

pera

ture

Def

eren

ce [K

]

0

4

8

12

16

20

Tran

smitt

ed E

lect

ricity

[MVA

]

Temperature Deference between Outlet and Inlet of Cable


Cable made with 2G HTS wire was energized in the grid in January 2008 & performed without any issues

Jan 8 2008


0

500

1000

1500

2000

2500

3000

3500

65 70 75 80Temperature [K]

Cri

tica

l Cur

rent

[A, a

t 1u

V/c

m]

Short Sample Ic(1800A at 77.3K)

Ic-T characteristicsof DI-BSCCO

0

500

1000

1500

2000

2500

3000

3500

65 70 75 80Temperature [K]

Cri

tica

l Cur

rent

[A, a

t 1u

V/c

m]

Short Sample Ic(1800A at 77.3K)

Ic-T characteristicsof DI-BSCCO

Commissiong Test(320m+30m Cable)

-0.5

0

0.5

1

1.5

2

2.5

0 500 1000 1500 2000 2500 3000Current [A]

Ele

ctri

cal F

ield

[uV

/cm

] Core-1Core-2Core-3

Ic criterion（1μV/cm）

73K69K

Variation of Critical Current from Phase-I through Phase-II

0

500

1000

1500

2000

2500

Sample Test Phase-I(after cooldown)

Phase-I(after long-term

operation)

Phase-II(after cooldown)

Phase-II(after long-term

opearion)

Cri

tica

l Cur

rent

[Adc

, at

73K

]

Core-1Core-2Core-3

• The Ic of long cable are very good match with expected value from short sample testing at 77K.

• The Ic values had no change through Phase-I and Phase-II including heat- cycles.


Variation of Temperature Difference on the Cable during Phases I & II

0

0.2

0.4

0.6

0.8

1

1.2

7/20 8/17 9/14 10/12 11/9 12/7 1/4 2/1 3/1 3/29 4/26

Date (2006-2007)

Tem

pera

ture

Def

eren

ce [K

]

0

4

8

12

16

20

Tran

smitt

ed E

lect

ricity

[MVA

]

Temperature Deference between Cable Outlet and Inlet


[ Phase-I ]

0

0.2

0.4

0.6

0.8

1

1.2

1/7 1/21 2/4 2/18 3/3 3/17 3/31

Date (2008)Te

mpe

ratu

re D

efer

ence

[K]

0

4

8

12

16

20

Tran

smitt

ed E

lect

ricity

[MVA

]

Temperature Deference between Outlet and Inlet of Cable


[ Phase-II ]

• Temperature difference between outlet and inlet of the HTS cable was 0.9 +/- 0.1K• Temperature deference was very stable during the long-term In-grid operation in

Phase I and Phase II• Maintained good CRS operation and No change of cable heat loss during long-

term in-grid operation


Presentation Summary

• World class team has successfully executed on all phases of the program– Met or exceeded all goals and objectives– Cable ran flawlessly for >12 months with ZERO instances of downtime due

to the HTS system– Efficient, reliable and robust design capable of handling ‘real-world’ utility

operating environment• ALL equipment/systems responded as designed without any adverse effects

– Biggest reliability concern (CRS) addressed & proven to meet commercial requirements

• Achieved World’s first in-grid demonstration of a YBCO device• Technology transfer & education achieved by numerous tours/events (>20) and

articles/presentations(>50) given throughout the program


The Bottom Line…

“Of importance to National Grid is that this project has demonstrated the reliability of the technology. We encountered no difficulties in integrating the project into our grid and the entire installation was totally transparent to our customers. The system has stood up to very exacting utility standards and we look forward to further developments in HTS technology.”

- William Flaherty,Energy Solutions Regional

Director of National Grid


Thank you!For more information:

www.superpower-inc.comor

[email protected]

12008년 12월 13일

Power System Network(345kV and above)

Power System Network(345kV and above)

345kV Overhead System

DC±180kV Cable Link

345kV Substation

Generating Plant

765kV Substation

765kV System

345kV Underground System

Legend

Classification 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008Peak Demand 37,293 41,007 43,125 45,773 47,385 51,263 54,631 58,994 62,285 62,794Increase Rate 13.0 10.0 5.2 6.1 3.5 8.2 6.6 8.0 5.6 0.8

Peak Demand [MW]Peak Demand [MW]

Voltage 2008 2010 2014 2020

765kV 21.7 24.4 23.6 25.3

345kV 50.050.0 57.257.2 56.656.6 57.957.9

154kV 49.4 49.2 50.050.0 54.054.0

Transition of Fault Current [kA]Transition of Fault Current [kA]

The rate of underground transmission lineThe rate of underground transmission line

IncheonIncheon29.5%29.5%

SeoulSeoul51.3%51.3%

JejuJeju11.9%11.9%

DaejunDaejun45.2%45.2%

GwhangjuGwhangju26.5%26.5%

UlsanUlsan18.7%18.7%

BusanBusan31.5%31.5%

KangwonKangwon5.3%5.3%

JunbukJunbuk6.1%6.1%

KyungbukKyungbuk4.1%4.1%

KyunggiKyunggi18.3%18.3%

KyungnamKyungnam7.4%7.4%

ChungnamChungnam5.0%5.0% DaeguDaegu

21.9%21.9%

(As of 2007)

ChungbukChungbuk6.2%6.2%

Total12.68%

High Capacitance & Low loss + Eco-friendlyHTS Cable & SFCL

High cost for civil work and constructionDifficulty of excavating roads for construction of conduit or

culvertNIMBY for the construction of new substations in urban areaNeeds for environmental friendly power apparatusNeed to decide how to renewal the aged power cablesElectric power demand is increasing every year Continuous increase of fault current

• Project period : 2004~2011• Total budget : $146million(Government : $100million / Industry : $46million)• Participants

The name of Project : DAPAS The name of Project : DAPAS ((Development of Advanced power system by applied Superconductivity technology)

22.9kV HTS Cable has been developed and 22.9kV HTS Cable has been developed and 154kV HTS power cable is under development till 2010154kV HTS power cable is under development till 2010

2004 2005 2006 2007200320022001

1 ‘st Phase 2 nd Phase

FundamentalDesign

SingleCore 30m

50MVA/30m3-Core

50MVA/100m3-Core

Fab. Evaluation.

1,000MVA

2008 2009 2010

3 rd Phase

Evaluation Type test Demonstration on Real grid

Real-grid application

Design Fab. Evaluation Type test

DAPAS

Year

Basic study

154kV

22.9kV

Long termOperation

그림 1. MLI 개략도

MLI

Vaccum

Tcold= 77K

Thot= 300K

Spacer

Outer layer

Inner layer

0 500 1000 1500 2000 2500 3000 350050

100

150

200

250

300

350

1E-6

1E-5

1E-4

1E-3

0.01

0.1

1 Temperature

Tem

pera

ture

(K)

Time (hr)

Vacuum rate

Vac

uum

rate

(Tor

r)

HTS Cable

Cryostat

Fabrication

Experimental result

Displacement Simulation

Seamless Aluminum Cryostat for HTS Cable was developedSeamless Aluminum Cryostat for HTS Cable was developedFundamental Studies

Pitch determinationfor each layer Impedance matching

EM field calculation

Fabrication

HTS Shield

HTS Conductor

Optimal Design for Conductor/Shield Stranding & FabricationOptimal Design for Conductor/Shield Stranding & FabricationDesign & Fabrication of HTS Cable

HTS CableHTS Cable• Cold Dielectric• Diameter : 145mm• Seamless Aluminum Cryostat• PVC Sheath• ~ 35kV Insulation level• 3 - phases in one cryostat• FC Stabilizer incorporated

HTS Cable

• 22.9kV (Nominal), 13.2kV (Phase)• 1,260A (50MVA)

Fault Current : 25kA, 15cycle (Cu Stabilizer)Closed loop cryo-coolers incorporated in CRS

HTS Cable SystemHTS Cable System

Joint BoxJoint Box• Compact Design

(500mm Ø, 3.5m L)• ~ 35kV Insulation level • Pre-fabricated components• Pressure withstand : Min. 15bar

Cable coreCable Cryostat Bellows

Approx. 3500


Approx. 3500Approx. 3500

Termination Termination • Compact Design

(800mm Ø, 3.5m L× 2.1m h)• ~ 35kV Insulation level • 3 - phases in one cryostat• Pressure withstand : Min. 15bar• Pre-fabricated components• Polymer composite Bushing

Approx. 3500

Appr

ox. 2

100

Insulator

BellowsCryostat

Approx. 3500

Appr

ox. 2

100

Insulator

BellowsCryostat

Design of Accessories

Pipe duct (175mm)Pipe duct (175mm)

TunnelTunnel

Snake and cleatsSnake and cleats(for TM behavior)(for TM behavior)

Installation & handling of HTS cable are same as ordinary cableInstallation & handling of HTS cable are same as ordinary cableInstalltion

PrePre--fabricated fabricated

••Jointing at site Jointing at site

TerminationTermination Joint BoxJoint Box

Minimum jointing work at site Minimum jointing work at site (14 days for termination, 21 days for joint box)(14 days for termination, 21 days for joint box)

PrePre--fabricated fabricated

Jointing Works

Configuration of CRS Configuration of CRS -- Closed loop ( no evaporation of LNClosed loop ( no evaporation of LN22 ) ) -- Total heat loss covered by packaged cryoTotal heat loss covered by packaged cryo--cooler cooler

GM840W@65K,

2EA

Separator

Sub-cooler

Ambient

HTS Cable & Acc.

Evaporator

Vacuum

Pump

Circulation

Pump

Heat

Exchanger

Pulse Tube

320W@65K

Stirling

Cryocooler

(640W @65K)

F

Coldbox1 Coldbox2

LN2Tank

(5 ton)

Bypass line

GM840W@65K,

2EA

Separator

Sub-cooler

Ambient

HTS Cable & Acc.

Evaporator

Vacuum

Pump

Circulation

Pump

Heat

Exchanger

Pulse Tube

320W@65K

Stirling

Cryocooler

(640W @65K)

F

Coldbox1 Coldbox2

LN2Tank

(5 ton)

Bypass line

CRS

Ground level

Joint box

Tunnel (55 m)

Pipe Duct [15 m]

Termination (Power source)Termination (Load)

Jointbox

U-bend

Termination (Load) Termination (Power source)

On the ground[30 m]

Configuration of system installation Configuration of system installation ( Fully simulating real grid conditions )( Fully simulating real grid conditions )

100 m

Evaluation

11stst Cool downCool down Reference Tests Load Cycle Test

•• Dielectric LossDielectric Loss•• Partial DischargePartial Discharge•• Dielectric securityDielectric security•• DC IcDC Ic

•• Applied Voltage Applied Voltage -- 1.5Uo for 30days1.5Uo for 30days

•• Load currentLoad current-- 1,260 A (8hrs On, 16hrs off)1,260 A (8hrs On, 16hrs off)

•• Cooling Circuit Pressure ControlCooling Circuit Pressure Control

•• DC Ic DC Ic •• PD (@Uo,1.5Uo, 2.5Uo)PD (@Uo,1.5Uo, 2.5Uo)•• Dielectric Loss (@Uo, 1.5Uo, 2.5Uo)Dielectric Loss (@Uo, 1.5Uo, 2.5Uo)•• Dielectric Security (@2.5Uo for 24h)Dielectric Security (@2.5Uo for 24h)••Thermal/Electrical loss (Ref.)Thermal/Electrical loss (Ref.)•• Impulse (BIL)Impulse (BIL)

Residual PerformanceTests

Warm-up & 2nd Cool down

•• Shrinkage (Ref.)Shrinkage (Ref.)

Test program Test program -- Reference tests for confirmation of sound installation Reference tests for confirmation of sound installation -- Main dielectric tests were executed after 2Main dielectric tests were executed after 2’’nd cool downnd cool down

Evaluation

Temperature profile during the whole type test procedureTemperature profile during the whole type test procedure

Referencetest

Residualtest

Test Results

Load Cycle Test at 1.5Uo for 30 days was successfully finishedLoad Cycle Test at 1.5Uo for 30 days was successfully finished

1 cycle

Time (h)

8h(1260A)

16h (No load)

Voltage

Current

(20kV ; 1.5U0)

Volta

ge &

Cur

rent

1 cycle

Time (h)

8h(1260A)

16h (No load)

Voltage

Current

(20kV ; 1.5U0)

Volta

ge &

Cur

rent

Test Results

* Background noise : 5~10 pC

PD, dielectric loss were tested successfullyPD, dielectric loss were tested successfully

Applied Voltage (kV) PD (pC) Tan δ

5 < 10 0.00002

10 < 10 0.000027

13.2 (Uo) < 10 0.000039

20.1 (1.5Uo) < 10 0.00004

33 (2.5Uo) < 10 0.000041

* High Frequency Antenna

Test Results

AC Dielectric Security Test @2.5Uo for 24hours was passed AC Dielectric Security Test @2.5Uo for 24hours was passed

Test Results

0 500 1,000 1,500 2,000 2,500 3,000 3,500

-2.0x10-3

0.0

2.0x10-3

4.0x10-3

6.0x10-3

8.0x10-3

1.0x10-2

1.2x10-2

1.4x10-2

1.6x10-2

Phase R @ 75K Phase S @ 75K Phase T @ 75K Phase R @ 72K Phase S @ 72K Phase T @ 72K

Ic criterion (1uV/cm)

Volta

ge (V

)

Current (A)

Phase(Cable)

Design @ 75 K

Result

75 K 72 K

R 3 kA 3.01 kA 3.34 kA

S 3 kA 3.06 kA 3.43 kA

T 3 kA 3.03 kA 3.34 kA

DC Ic showed no degradation after all electrical & thermal cycleDC Ic showed no degradation after all electrical & thermal cycle teststests

* Operating temperature : 72 ~ 75 K* Operating current range : ~ 1.8 kA

Operating range

Test Results

•• The 22.9kV 50MVA HTS cable system was developedThe 22.9kV 50MVA HTS cable system was developed

and successfully passed 3 and successfully passed 3 rdrd party inspected type testparty inspected type test

•• The proposed type test specification fully considers The proposed type test specification fully considers

the realthe real--grid operational conditionsgrid operational conditions

•• Long term verification in end userLong term verification in end user’’s reals real--grid has beengrid has been

planned for commercialization of HTS cable systemplanned for commercialization of HTS cable system

In 2008, the main topic of R&D on the HTS cable system is In 2008, the main topic of R&D on the HTS cable system is operation and maintenance skills regarding to the real grid operoperation and maintenance skills regarding to the real grid operationation

• History

• 2001 ~ 2003 : Fundamental studies • 2004 ~ 2005 : Application technologies • 2006 ~ 2007.6 : Type test for 22.9kV products

HTS Cable, Joint, Terminations, CRS

• Updated

• 2007.6 ~ 2008 : O&M Skills & 6 Times Thermal CyclesUnmanned operation Technology, Live line maintenance

• Planning

• 22.9kV 50MVA : Real grid application in KEPCO’s substationLonger than the length which needs joint box with network study

HTS Cable Updated

3phase 22.9kV/630A hybrid SFCL(2006)

Developed jointly by KEPRI and LS Industrial Systems.Combined Superconductor and normal-conductor devices.A 3φ 22.9 kV/630 A SFCL was built and tested for 3-phase faults

• Limited fault current 29 kA to 17 kA (and to 8 kA after 5 cycles)

A hybrid SFCLunder test

Cryostat Fast Switch Current Limiting Resistor

Control & Monitoring Parts

Last version of 3phase 22.9kV/630A hybrid SFCL(2008)

Field test of 22.9 kV Hybrid SFCL is planned in Gochang Testing Yard.Now, processing the network engineering

Superconducting power machine testing building

AutomaticFault generator

Reliability Test Plan

KEPCOHead Quarter

Prime Contractor

KEPCO(KEPRI)KERI

UniversityDetailed Feasibility

StudyOperating & Maintenance

Korea GovernmentKETEP

(Korea Institute of Energy and Resources Technology

Evaluation and Planning)

KEPCO(KEPRI)LS Cable

KERI, KBSiUniversity

Manufacture and Installation in HTS

Cable Systems

KEPCO(KEPRI)LS IS

UniversityManufacture and

Installation in SFCL Systems

• Project period : Nov. 2008 ~ Oct. 2013• Total budget : $17million

(Government : $8.5million/Industry : $8.5million)

154/22.9kV MTR

HTS Cable 500m

150MVA HTS Cables

3kA SFCL

[ 22.9kV HTS Cable, Termination, and Splice]

[ 22.9 kV SFCL System-Trial Product ]

Supplying the huge buildings with electric power by HTS cables

Replacing 22.9kV conventional cables(2~3lines) with the superconducting cables using the existing conduit or culverts without additional civil works

22.9 kVSW/S

22.9 kV Superconducting Cablesto replace 154 kV conventional cables

~

154 kV S/S in the suburbs

SFCL

SFCL

SFCL

22.9 kVSW/S

22.9 kV Superconducting Cablesto replace 22.9kV conventional cables

Superconducting Transformers

22.9 kVSW/S

Downtown Area

Circuit Breaker(Normal open)

Superconducting Power System (SPS) applying distributed switching stations for metropolitan areas

Apply superconducting power devices (cables, transformers, FCLs) to real power system154kV transmission power system 22.9kV superconducting power system

Replace 154kV substations in downtown with 22.9kV underground switching stationsReplace 154kV conventional cables with 22.9kV superconducting cablesBulk power transfer by superconducting cables and transformers & Fault current reduction by SFCL

Skip substations

Reduce construction costs

Environment-friendly

Avoid civil petitions

154kVS/S

154kVS/S

154kVS/S

154kVS/S

Downtown

154kV conventional cables

154kVS/S

154kVS/S

22.9kVSW/S

22.9kVSW/S

22.9kVSW/S

22.9kVSW/S

22.9kVSW/S

22.9kVSW/S

22.9 kVSuperconducting cables

Downtown

154kV conventional cables

Suburb Suburb

One of solutions for the site problemNo substations & Compact size Easy to find a site for power facilities in downtownUnderground switching stations Make a park on the switching stations

Economic benefitsReduction of cost for buying land

The site for 22.9kV switching stations is less than 30%, compared to 154kV substations.

No additional construction costWe can use established underground facilities such as existing electric power conduit pipes.

Environmental and social benefitsEnvironment-friendly Avoid the trend of NIMBY

No oil for cooling the systemFree of the explosion danger (Superconducting transformer)

No additional construction Reduce the construction cost and ease traffic congestionHigh efficiency and loss of superconductor Save energy and reduce CO2 emission

In Korean power system, increase of electric power demand have been accompanied with increase of power plants, substations, transmission lines and distribution lines. So that development of high capacitance power facility to accept increase demand was required and during a past decade, superconducting cable and SFCL have been developed.

Currently, developments and tests of 22.9kV superconducting cable and SFCL are finished, and development of 154kV superconducting system is under development till 2010.

From Nov.2008, to affirm stability and reliability of developed superconducting cable and SFCL by gathering and analysis of operating and maintenance data, 22.9kV HTS system real grid project is started for 5 years.

If stability of HTS system including superconducting cable and SFCL is affirmed, it will be expended from urban.

2008년 12월 13일 39

Southwire – Entergy HTS Cable Project

David KnollProject Manager

HTS Cable Systems

Eigth Annual EPRI Superconductivity ConferenceOak Ridge, TN

November 12-13, 2008

Erik GuillotProject Manager

Transmission EMCC

Project Partners

Project Specs

Cable Design HTS TriaxTM - SuperconductingLength 1760 meters (1.1 miles)Voltage 13.8 kVLoad 48 MVACooling Single Point, Closed CycleSplices 2 (Cable Sections = 3)In-Service Date 1Q2011

Cooling Plant13.8 kV, 2.0 kA (48 MVA) Triax HTS Cable

Project Location

Cable Route

Project Overview: Replace Copper HV Transmission with HTS MV Distribution

Problem:• Saturated 13 kV distribution – anticipate high load growth• 230/13 subs to north & south of area - Need new sub at mid-point

Challenges:• OH RoW for 230 or 13 kV very difficult or impossible• Small footprint available for new substation• 230 kV solution: placing transformer in dense residential area.• 13 kV conventional: Voltage drop, power quality

Solution:• 13 kV HTS cable to transmit 48 MVA into small footprint station.• 1.1 mile HTS cable that meets load growth needs.• Leverage existing transformer capacity – No new transformers needed• Single point cooling station.• 13 kV HTS replaces 230 kV underground.• Cost effective with DOE support.

Southwire - HTS TriaxTM 2000A Cable

CryostatFormer Phase 1 HTS

Phase 2 HTS

Dielectric

Phase 3 HTS

Copper Neutral

LN

LN

HTS TriaxTM Advantage vs Competition:1. ½ HTS tape usage = substantially cheaper2. Single Cable = simplified mfg & installation3. Smaller cold surface area = lower cooling & operating cost

Southwire Triax Cable Termination

3 Phase Connections

Neutral Connection

- Provides transition from superconducting materials to copper materials.

- Thermal transition from –200 C to ambient temperature

- Controls electrical stresses.

- Provides input and/or output location for LN coolant.

- Provisions made for temperature and pressure measurements and monitoring.

- Electrical connections to utility made by means of industry standard NEMA pad.

Cable Installation

On Going Effort - HTS Tape Options

• 1G BSCCO vs 2G YBCO– Mechanical testing– Compatibility with cabling process– Electrical Properties – Ic, n-Value, AC Loss– Magnetic Properties– Piece Lengths– Wire availability– Per meter costs

On Going Effort – Cable Configuration

1G 2GComposite 1 1G

Segment 1 Segment 2 Segment 3 Spare

1G 2G2G 1G

1G 1G

2G2G

1G

1G 1G

2G 2G

Composite 2

All 1G

All 2G

On Going – Thermal / Hydraulic Analysis

Former, RT

Heater - Qknown

Insulation – RT

Heater - Qknown

Insulation – RT

Heater - Qknown

Insulation – RT

Cryostat WallLN2

LN2

Temp Sensors

THERMAL MODEL

Former, RT

HTS – AC Loss, RT

Insulation – RT

HTS – AC Loss, RT

Insulation – RT

HTS – AC Loss, RT

Insulation – RT

Cryostat WallLN2

LN2

CABLE ASSEMBLY

66

67

68

69

70

71

72

73

74

0 500 1000 1500 2000L [m]

T [K

]

AnnulusFormerTmaxPh1Ph2Ph3Neutral

On Going Effort – Cryogenic System Design

• ~ 10kW cooling required

• Closed loop cooling system

• Cryocooler Options– Pulse Tube– Sterling Cycle– Brayton Cycle

• RFP’s out after AC Loss study

• System supplier will perform detailed system design

Heat ExchangerClosed Cycle

n…

HTS Cable

Back-upOpen Cycle

21

Cryocooler Bank

LN2Tank

Sub-Cooled LN2Counter Flow Cooling

Out = thru formerIn = thru annulus

Previous Experience – AEP, Columbus, OH

AEP-Bixby200 meters8/2006 to present13.2 kV, 3.0 kA,Triax Cable

5 DAY Bixby Peak Load – August 2007

Peak Load = 2,715 A

0

500

1000

1500

2000

2500

3000

0:00:00 0:00:00 0:00:00 0:00:00 0:00:00

Cur

rent

(Am

ps)

Phase 1

Phase 2

Phase 3

Neutral

AEP Data – Fault Currents

07/11/200801:24:20.500

07/11/200801:24:27.425

No measurable thermal response in HTS cable or terminations.

• Transient event: I ≥ 3.0 kA (2,121 A-rms)

• 74 total events– 39 events with >4,242 A-pk (3,000 A-rms)– 19 events with >5,657 A-pk (4,000 A-rms)– 13 events with >7,071 A-pk (5,000 A-rms)– 7 events with >14,142 A-pk (10,000 A-rms)– Highest current = 17,765 Apk (222

milliseconds)– Longest duration = 1.785 seconds (5209

Apk, 3683 Arms)

• HTS cable never taken out of service.

1 /31

“ Evaluation of 100m long 22.9kV 50MVA HTS Cable System”

S. K. LEEPrincipal Research EngineerElectric Power R&D CenterLS Cable Ltd

EPRI Superconductivity Conference

Development status up to 154kVDevelopment status up to 154kVHTS Cable Systems in KoreaHTS Cable Systems in Korea

12 Nov. 200812 Nov. 2008

KEPRI (KEPCO)KEPRI (KEPCO)ByeongByeong--Mo YangMo Yang

2 /31

Contents

About DAPAS program

• R&D Results of HTS cable in 1st & 2nd Phase

• Plan of 3 rd Phase

• Conclusion

3 /31

DAPAS program

DAPAS program

• Development of Advanced Power system by Applied Superconductivity tech.• Name of the “superconductivity frontier program in Korea”• Selected on May. 2001 by MOST• Funded about 100 million US dollars for ten years from government.

The primary target

• R & D and commercialization of the developed HTS products

Budget

10 years(2001~2010) 148 million $ ( Gov. : 100 & Ind. : 48 )

2007. 04 - 2008. 03 14 million $ ( Gov. : 10 & Ind. : 4 )

4 /31

Development targets for each phase

FY

Phase

Target

2001 2002 2003

1st Phase

Core technology(to develop the HTS wire and system technology)

2004 2005 2006

2nd Phase

Pre-commercial pilot(to improve the 1st

phase technology and develop the prototype devices)

2007 2008 2009 2010

3rd Phase

Commercialization(Field test and development of the industrial technology for commercialization)

Power cables

50MVA, 22.9kV cable

50MVA, 22.9kV, 100m system

1GVA, 154kV, 3 phase

Transformers

Fault-current limiters

Motors

1MVA, 22.9kV Single phase

6.6kV, 200Arms SFCL

100~ hpmotor

core technologies

22.9kV, 630Arms SFCL

1MVA~motor

33MVA, 154kV Single phase

22.9kV, 3kA & 154kV, 4kArms

5MVAmotor

5 /31

30m 100m 200m 350m 500m

50m 120m

36kV

66kV

138kV

154kV

225kV

NKT (~02)

SEI (~99)

SEI & TEPCO (~01)

24kVPirelli, AMSC,

DTE (~01)12.5kV

S’wire & IGC (~00)

620m

34.5kV

77kVFurukawa (~04)

22.9kV

250m

3 phase, 1 cryo, CD Succeeded DAPAS Warm Dielectric 1G wire3 phase, 3 core, CD Failed Cold Dielectric 2G wire3 phase, 3 core, WD1 phase, CD 1 core 3 ph

DAPAS(~04)

(~07)

DAPAS (~11) LIPAAMSC&Nexans

LIPA (~07)

Albany

AEP

S’wire & NKTAMSC (~07)

IGC & SEI (~07)

1,780m

13.8kV

S’wire &NKT(~11)

SPE project

SPELIPA 2

AMSC&NexansLIPA (~11)

SEI&TEPCO(~11)

Highest voltage class

6 /31

History of HTS power cable in DAPAS

5m Cable core + 10m Cooling System

30m Single Phase HTS Cable System22.9kV, 50MVA

30m Three Phase HTS Cable System22.9kV, 50MVA

2001 2003 2005Aug., 2005Long Term Test

7 /31

Termination (Load)Termination (Load)

Ground levelGround level

Joint boxJoint box

Termination (Load)Termination (Load) Termination (Power source)Termination (Power source)

Tunnel (55 m)Tunnel (55 m)

Pipe Duct [15 m]Pipe Duct [15 m]

Termination (Power source)Termination (Power source)

JointJointboxbox

UU--bendbend

On the groundOn the ground[30 m][30 m]

Fully simulating real grid conditions

HTS Cable in KEPCO Testing Center in 2006

8 /31

Specification

• Voltage : 22.9kV (Nominal), 13.2kV(Phase)

• Current : 1,260A (50MVA)

• Fault Current : 25kA, 15cycle

• Cryogenic system : Closed loop cryo-coolers

• Cable length : 100m

Cable

Approx. 3500

Appr

ox. 2

100

Insulator

BellowsCryostat

Approx. 3500

Appr

ox. 2

100

Insulator

BellowsCryostat

Termination Joint Box


Approx. 3500


Approx. 3500Approx. 3500

9 /31

Pipe duct (175mm)

TunnelTunnel

Snake and cleatsSnake and cleats

Installation & handling of HTS cable are same as ordinary cable

Installation

10 /31

• Specification of type-test - Optimal test items & conditions - Suitable to real grid application

Proposed to IEC SB1 by LS Cable ( under discussing )

• Certification by 3rd party test institute- Kinetrics, Canada

• Confirmation by end user- KEPCO/KEPRI- Gochang power testing center

Evaluation

11 /31

Load Cycle Test at 1.5Uo for 30 days was successfully finished

1 cycle

Time (h)

8h(1260A)

16h (No load)

Voltage

Current

(20kV ; 1.5U0)

Volta

ge &

Cur

rent

1 cycle

Time (h)

8h(1260A)

16h (No load)

Voltage

Current

(20kV ; 1.5U0)

Volta

ge &

Cur

rent

Test Results (I)

PD and dielectric loss were tested successfully

* Background noise : 5~10 pC

Applied Voltage (kV) PD (pC) Tan δ

5 < 10 0.00002

10 < 10 0.000027

13.2 (Uo) < 10 0.000039

20.1 (1.5Uo) < 10 0.00004

33 (2.5Uo) < 10 0.000041

* High Frequency Antenna

12 /31

AC Dielectric Security Test @2.5Uo for 24hours was passed

Test Results (II)

No degradation after all electrical & thermal cycle tests

0 500 1,000 1,500 2,000 2,500 3,000 3,500

-2.0x10-3

0 . 0

2 . 0 x 1 0-3

4 . 0 x 1 0-3

6 . 0 x 1 0-3

8 . 0 x 1 0-3

1 . 0 x 1 0-2

1 . 2 x 1 0-2

1 . 4 x 1 0-2

1 . 6 x 1 0-2

P ha se R @ 7 5 K P ha se S @ 7 5 K P ha se T @ 7 5K P ha se R @ 7 2 K P ha se S @ 7 2 K P ha se T @ 7 2K

Ic criterion (1uV/cm )

Volta

ge (V

)

C u rren t (A )

Operating range Phase(Cable)

Design @ 75 K

Result

75 K 72 K

R 3 kA 3.01 kA 3.34 kA

S 3 kA 3.06 kA 3.43 kA

T 3 kA 3.03 kA 3.34 kA

* Operating temperature : 72 ~ 75 K* Operating current range : ~ 1.8 kA

13 /31

AC Loss was measured by calorimetric method on site

AC Loss

Loss (W)

W/m.phase @ 1260ArmsDesign Measured

Heat Loss AC loss Total Heat Loss AC loss Total

Cable

70m 165.0 210.0 375.0 164.8 255.2 420.0 AC loss : 1.21 W/m∙phase

30m (U-band)

105.0 90.0 195.0 102.9 113.2 216.1 AC loss : 1.25 W/m∙phase

Termination 165.0 135.0 300.0 180.0 157.6 337.6

• 0.8W/m·phase @ 1260Arms in the Lab

14 /31

Plan (the 3rd phase)

15 /31

Target of 3rd phase (2007 ~ 2011)

R&D of 154kV, 1 GVA HTS Cable

- Specification : 154kV, 1GVA, 3phase, 100m

- Install the Power Grid in KEPCO Testing Center

154kV 2000SQ 154kV 2000SQ XLPE 2 LIneXLPE 2 LIne

154kV Over Head Line154kV Over Head Line(Youngkwang Nuclear Plant))(Youngkwang Nuclear Plant))

300m300m

TunnelTunnel

100m100m

Substation at GochangSubstation at Gochang

154kV HTS Cable will be installed in 2010

16 /31

25621

35851

24577

32996

27320

37293

30327

41007

32559

43125

34985

45773

36809

47385

39057

51246

41625

54631

43513

58994

0

10000

20000

30000

40000

50000

60000

70000

Capa

cita (

MW

)

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year

Peak loadAverage load

Peak and average load for a year

After 1997 financial crisis in Korea

Last year 2007, over

60GW

17 /31 17

Status and Analysis of KEPCO Grid

SeoulRegion

42%

East Region7%

Middle Region

13%

South-WestRegion

8%

South-East Region

30%

1) Regional Load : Highest Seoul Region (42%)

2) Underground Cable among T/L : Highest Seoul Region (73.9%)

3) Increasing Underground T/L : about 12.68% (the rate of Underground T/L in Korea)

VoltageVoltage T/L LengthT/L Length Rate(%)Rate(%)

345kV345kV 9393 77

154kV154kV 1,1431,143 9292

66kV66kV 1313 11

단위 :C-Km

Necessity of Transmission HTS Cable in KEPCO

IncheonIncheon29.5%29.5%

SeoulSeoul51.3%51.3%

JejuJeju11.911.9%%

DaejunDaejun45.2%45.2%

GwhangjuGwhangju26.5%26.5%

UlsanUlsan18.7%18.7%

BusanBusan31.5%31.5%

KangwonKangwon5.3%5.3%

JunbukJunbuk6.1%6.1%

KyungbukKyungbuk4.1%4.1%

KyunggiKyunggi18.3%18.3%

KyungnamKyungnam7.4%7.4%

ChungnamChungnam5.0%5.0% DaeguDaegu

21.9%21.9%

(As of 2007)

ChungbukChungbuk6.2%6.2%

Total12.68%

18 /31 18

Necessity of Transmission HTS Cable in KEPCO

HTSSuperconductor

LN2

150 mmHTS SC Cable

(154kV, 3.75kA, 1cct)800 mm

OF Cable (345kV, 840A, 2cct)

Cu Conductor150mm

19 /31 19

Applying Scenario of Transmission HTS Cable

154kV Overhead Line

:Suburbs Large City

154kV Conventional Cable

154kV HTS Cable

: Center of Large City, high load density

345kV Substation

Considerable Places for Applying HTS Cable to KEPCO Grid

Replacement from Old Conventional Cable

Construction of New T/L in Large City

Enlargement of T/L due to increasing load in Large City

Applying Concept of Transmission HTS Cable in KEPCO

20 /31

C

A B

Ia

IbIc

ISa

ISb ISc

15kA3kA 12kA9kA6kA

Fault Analysis of 154kV HTS Cable by Using EMTDCFault Analysis of 154kV HTS Cable by Using EMTDC

Modeling of Transmission HTS Cable in KEPCO

21 /31

HTS Phase ConductorHTS Phase Conductor

Outer CryostatOuter Cryostat

Former/StabilizerFormer/Stabilizer

InsulationInsulation

HTS ShieldHTS Shield

LN2LN2

Inner CryostatInner Cryostat

Thermal InsulationThermal Insulation(MLI + Vacuum)(MLI + Vacuum)

• Electrical Characteristics

- Rated Voltage : 154 kV

(U0, Um = 89, 170 kV)

- Rated Current : 3.75 kA

- BIL : 750 kV

- Design Fault Current

: 50 kA, 1.7s

• Physical Characteristics

- Cold Dielectric Design

(Single Phase in One Cryostat)

Design of 154kV/1GVA HTS Cable

154 kV, 1GVA HTS Cable Cross Section 154 kV, 1GVA HTS Cable Cross Section

22 /31

154kV/1GVA Stabilizer Design

-Fault Condition : 50 KA/ 1.7s

15.5 cycle10.5 cycle

5.5 cycle

Stabilizer Size Min. 610 mm2

Temp. Limit : 94 K (5 bar)Initial Temp. : 77 K

Core Design for 154kV/1GVA HTS Cable

23 /31

HTS Wire Evaluation for Cable Application

The Mechanical & Thermal Properties of multi-kinds of HTS wires evaluated

Multi-BendingTential Stress

Thermal Cycling & Twisting

24 /31

Insulation Design of 154kV HTS Cable

Breakdown s trength [kV/mm]

Bre

akd

ow

n w

eib

ull p

rob

ab

ility [

%]

757065605550454035

99

90

8070605040

30

20

10

5

3

2

1

0.1

25.18 68.39 15 0.633 0.088

26.39 61.65 15 0.310 >0.250

20.19 55.76 15 0.431 >0.250

Shape Scale N AD P

100

125

170

Variable

y = 40.043x-0.0514

y = 40.175x-0.0235

y = 51.097x-0.0336

0

5

10

15

20

25

30

35

40

45

50

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06T ime [s e c ]

Bre

akd

ow

n v

olt

ag

e [

kV

]

11

100 125 170

Breakdown s trength [kV/mm]

Bre

akd

ow

n w

eib

ull p

rob

ab

ility [

%]

13012011010090807065

99

90

8070605040

30

20

10

5

3

2

1

0.1

16.10 120.6 15 0.540 0.164

17.47 110.8 15 0.543 0.160

17.64 100.9 15 1.092 <0.010

Shape Scale N AD P

100

125

170

Variable

• PPLP for EHV application

• Insulation Thickness

< 15mmt

• Overall Diameter < 145mm

AC Weibull Test

AC V-t Test

Impulse Weibull Test

25 /31

DC 15,000 Amp / 5V

[ DC power supply ][ Cryogenic Vessel for Variable Temp.]

Cryogenic Characteristic Test of 154kV/1GVA HTS Cable

66K~77K, 5bar

26 /31

Termination of 154kV/1GVA HTS Cable

27 /31

5600W @ 65K

Phase APhase A

Phase BPhase B

Phase CPhase C

CryoCryo--CoolerCoolerLNLN22

StorageStorage

LN2 FlowLN2 Flow

Cryogenic System of 154kV/1GVA HTS Cable

28 /31

Place : Gochang Testing Center

Design : 2007.11

Start : 2008.3

Finish : 2009.9

Testing Facility for HTS Cable by KEPCO

154kV Superconducting Cable Test will be start 2009.6

29 /31

PQ시험장 OF케이블시험장

GIL시험장

교량첨가시험장

열거동시험장

시료설치용

전력구

배선용전력구

초전도시험장

HTS Cable Test Field (Tunnel)

Testing Facility Design

30 /31

2008. 6. 9 Berlin Germany11th IEC TC90 Meeting,

Proposed the Test Procedure the HTS Cable, like as Ic Measurement Procedure.Suggest the round robin test the HTS cable for standard

Status of Standard for HTS cable

2008. 8. 27, Paris FranceCIGRE SCD1 Working Group Meeting WG.15(Superconducting and Insulating Materials for HTS Power Applications)

Proposal the Specification of HTS ApplicationProposals for test procedures of HTS power equipment and electrical insulation.

CIGRE SC B1 (Insulated Cable) Decide to make TF for studying the specification of HTS cable

Korea The KS (Korean Standard) is in progress for “Ic Measurement Procedure of HTS Cable”

31 /31

Conclusion

• The 22.9kV 50MVA HTS cable system was developed

and evaluated

• 154 kV , 1GVA HTS cable system is being developed in the 3rd

Phase of DAPAS program

< 21/21 >

• HTS Cable R&D is moving from Grid Test to Grid Use in the world

• Suggestion on the Collaboration for studying

Standard of HTS Cable Testing Procedures

32 /31 < 21/21 >



Status of 2G HTS Wire Technology Development and Manufacturing at SuperPower

Chuck WeberY.-Y. Xie, Y. Chen, X. Xiong, K. Lenseth, M. Marchevsky, A. Rar, Y. Qiao, B. Gogia, A. Knoll, R. Schmidt, D. Hazelton, and V. Selvamanickam

EPRI 8th Annual Superconductivity Workshop, November 12-13, 2008, Oak Ridge, TN

Funded by Title III Program, DOE and AFRLSupported by CRADAs with Los Alamos, Oak Ridge, & Argonne National Laboratories

2EPRI 8th Annual Superconductivity Workshop, November 12-13, 2008, Oak Ridge, TN

SuperPower’s 2G wire is based on high throughput processes & superior substrate

YBCO

LaMnO3

MgO (IBAD + Epi layer)

Al2O3

100 nm

Y2O3

Hastelloy C-276

YBCO

LaMnO3

MgO (IBAD + Epi layer)

Al2O3

100 nm100 nm100 nm

Y2O3

Hastelloy C-276

2 μm Ag

20μm Cu

20μm Cu50μm Hastelloy substrate

1 μm YBCO - HTS (epitaxial)~ 30 nm LMO (epitaxial)

~ 30 nm Homo-epi MgO (epitaxial)~ 10 nm IBAD MgO

< 0.1 mm

• High throughput is critical for low cost 2G wire and to minimize capital investment• SuperPower’s 2G wire is based on high throughput IBAD MgO and MOCVD

processes• Use of IBAD as buffer template provides the choice of any substrate• Advantages of IBAD are high strength, low ac loss (non-magnetic, high resistive

substrates) and high engineering current density (ultra-thin substrates)


SuperPower’s 2G pilot manufacturing facility has been operational since 2006

Pilot IBAD

Pilot Substrate Electropolishing

Pilot buffer Sputtering

Pilot MOCVD

• Majority of investment already made for 1000 km/year capability


Our main objective in 2008 was to meet market requirements for 2G wire• Replace 1G wire in large HTS device demonstration projects in the

U.S. and around the world– Key requirements: Long length, availability, Ic, price

• Supply large volumes of 2G wire to customers who have been waiting to take advantage of the superior performance of 2G

– Key requirements: Long length, Ic, additional performance metrics such as in-field Ic, ac losses, joints, insulation, FCL metrics …

• Advance towards medium-term goal of replacing copper wire in commercial HTS projects and challenge LTS wire in high-field applications

– Key requirements: Long length, availability, Ic, price, in-field performance and other additional performance metrics


High current metric: Capability of ~ 1000 A in 12 mm widths achieved!

2005 SmYBCO

2006 SmYBCO

2007 GdYBCO

0

1

2

3

4

5

6

7

0 1 2 3 4

Thickness (μm)

Jc (M

A/c

m2 )

2008 (GdY)BCO

3.3 μm film made in 10 passes: Ic = 976 A = 833 A/cm (Jc = 2.44 MA/cm2)2.1 μm film made in 6 passes: Ic = 929 A = 774 A/cm (Jc = 3.68 MA/cm2)

All achievements using production buffer tapes

Ic measurement using continuous dc current (no pulsed current) across entire tape width of 12 mm. No patterning

Over 1+ m length,Ic = 976 A = 813 A/cm

2008 (GdY)BCO

2005 SmYBCO

2006 SmYBCO

2007 GdYBCO

0100200300400500600700800900

0 1 2 3 4Thickness (μm)

Criti

cal c

urre

nt (A

/cm

-wid

th)


High current technology is being transferred to pilot MOCVD

0 5 10 15 20 25 30 35 40 45 50 550

100

200

300

400

500

Ic (A

/cm

-w)

Position (m)

Minimum Ic > 400 A/cm-w over 55 m length

Over 55 m length,

Minimum Ic = 481 A = 401 A/cm

At 0.2 μV/cm voltage criterion

All achievements using production buffer tapes. MOCVD process speed 90 m/h (4mm equivalent)

Over 10 m length,

Ic = 481 A = 401 A/cm

At 0.1 μV/cm voltage criterion

-1.0E-07

0.0E+00

1.0E-07

2.0E-07

3.0E-07

4.0E-07

5.0E-07

0 100 200 300 400 500

Current (A/cm-w)

Volta

ge (V

/cm

)

Ic = 450 A/cm-w at 0.1 μV/cm voltage criterion


In-field performance metric: dramatic improvements achieved by Zr doping

BZO additions have been very effective in improving in-field performance of PLD films, but was yet to be demonstrated with MOCVD.

Gd substitution results in strong pinning parallel to the tape.Zr doping strongly enhances pinning perpendicular to tape & in intermediate fields2 to 2.5x improvement in Ic by Zr doping. Thin films and thick films

020

4060

80100

120140

160180

-20 0 20 40 60 80 100 120

Angle between field and tape (deg)

Ic (A

/cm

)

0.7 micron SmYBCO

0.7 micron GdYBCO

0.7 micron Zr:GdYBCO

77K, 1T 77K, 1 T0

50100150200250300350400450

-20 0 20 40 60 80 100 120

Angle between field and tape (degrees)Ic

(A/c

m)

3.5 micron SmYBCO2.8 micron GdYBCO

3.3 micron Zr:GdYBCO

Data from Y. Zhang, M. Paranthaman, A. Goyal, ORNL

186 A/cm

229 A/cm


Excellent in-field performance at 65 K, 3 T

150

200

250

300

350

400

450

500

550

-20 0 20 40 60 80 100 120Angle (deg)

• Title III Phase 3 program goal is Je without stabilizer of 15,000 A/cm2 at 65 K, 3 T

• Minimum Ic = 267 A/cm corresponds to Je of 41,000 A/cm2 at 65 K, 3 T

• Ic perpendicular to tape = 340 A/cm corresponds to Je of 52,300 A/cm2

2007: 2.8 μm(Y,Gd)BCO

2008: 3.15 μmZr:(Y,Gd)BCO

2008: 3.33 μmZr:(Y,Gd)BCO

160 A/cm

181 A/cm

2007 (Gd,Y)BCO

67%267 A/cmMinimum Ic

88%340 A/cmB // c

Improvement2008 Zr-doped (Gd,Y)BCOIc (77 K, 1 T)



Zr-doped chemistry has been successfully transferred from Research system to Pilot MOCVD

0102030405060708090

100110120130140150160

-20 0 20 40 60 80 100 120 140 160 180Angle between magnetic field & tape (degrees)

Crt

ical

cur

rent

(A)

(Y,Sm)BCO(Y,Gd)BCO(Y,Sm)BCO with Zr(Y,Gd)BCO with Zr


Long-length wires are now being produced with Zr-doped chemistry


In 2007, we demonstrated world record high-field magnet

SuperPower coil tested in NHMFL’s unique, 19-tesla, 20-centimeter wide-bore, 20-megawatt Bitter magnet

05

1015202530

0 50 100 150 200 250

Current (A)

Cen

tral

Fie

ld (T

)

19T background self field

26.8 T @ 175 A

9.81 T @ 221 A

78 A in 4 mm width (77 K, self field)

Average Ic of wires in coil

~ 462 m2G wire used

12 (6 x double)# of Pancakes

~ 87 mmWinding OD

19.1 mmWinding ID

9.5 mm (clear)Coil ID

Coil tested by H. Weijers, D. Markewicz, & D. Larbalestier, NHMFL, FSU

0.73 T generated by coil at 77 K


New coil in 2008 with Zr-doped (Gd,Y)BCO wire with better in-field performance

~ 44.4

~1.569

~ 2772

~ 462

6

~ 51.6

~ 87

19.1

9.5

2007 coil

2008 coil

~1.635Coil Je (A/mm2) per amp of operating current

~ 2664# of turns

~ 41.9Coil constant (mT/A)

~ 4802G tape used (m)

6# of double pancakes

~ 56.7Coil Height (mm)

~ 87Winding OD (mm)

28.6Winding ID (mm)

21Coil ID (mm) clear 72 to 9772 – 82Wire Ic (A) 4 mm

2008 coil2007 coil


30% higher field in 2008 coil made with wire with improved in-field performance

0

5

10

15

20

25

30

35

-20 0 20 40 60 80 100 120 140 160

Angle between field and wire (degrees)

Ic (A

) for

4 m

m w

ide

wire

(Y,Sm)BCO wire 2007 coil(Y,Sm)BCO wire 2007 coilZr:(Gd,Y)BCO wire for 2008 coilZr:(Gd,Y)BCO wire for 2008 coil

77 K, 1 T (ORNL)

75 K, 0.92 T (LANL)

Temperature Coil current

Max Central Field

(K) (A) (T)77.4 22.7 0.95

70.25 44 1.8465.8 54 2.2664.5 57 2.3963.8 58 2.43

0.73 T

2007 coil with (Y,Sm)BCO

2.39 T65 K

30%0.95 T77 K

Improvement2008 coil with Zr-doped (Gd,Y)BCO

Temperature


This improvement remains effective at low T

0.75

1.00

1.25

1.50

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

B[Tesla] at 30o w.r.t. the tape surface

[Ic/Ic

@ 7

7K 0

T- 2

008]

/[Ic/

Ic@

77K

0T-

2007

] 60 K50 K40 K30 K20 K

Measurement done by M. Ogata and K. Nagashima at Railway Technical Research Institute

20-35% improvement in magnetic field range up to 4T

T =


Continued routine manufacturing of kilometer lengths of fully buffered tape in CY 2008

4

5

6

7

8

0 200 400 600 800 1000 1200 1400 1600Tape position (m)

In-p

lane

text

ure

(deg

rees

)

12 tapes with complete 5-layer buffer stack, by ISS2007, and now over40 tapes have been produced in lengths of 1,300 m to 1,500 with in-plane texture of 5 – 7 degrees and excellent uniformity of ~2%

Manufacture of kilometer-lengths of high quality, fully-buffered tape was routine throughout 1 year


Challenges in fabrication of complete, kilometer long 2G wire

Kilometer lengths limited by a few bad regions in an otherwise uniform wire;Major sources of the problems identified:

– MOCVD instability;– Mechanical damage;– Substrate defects

0

50

100

150

200

250

0 200 400 600 800 1000

Position (m)

Ic (A

/cm

)

050

100150200250

0 200 400 600 800 1000Position (m)

Ic (A

/cm

)

0

100

200

300

400

0 200 400 600 800 1000Position (m)

Ic (A

/cm

)


Aug. 2008: Yet another world record!

0

50

100

150

200

250

300

350

400

450

0 200 400 600 800 1000

Position (m)

Ic (A

/cm

)

77 K, Ic measured every 5 m using continuous dc currents over entire tape width of 12 mm (not slit)

Voltage criterion = 0.2 microvolt/cm

Except for three spots, Ic of rest of 1,030 m > 300 A/cm 4mm: 120 A

200 mIc > 350 A/cm4 mm: 140 A

320 mIc > 350 A/cm4 mm: 140 A

310 mIc > 350 A/cm4 mm: 140 A

233,8102271030190,260302630181,980337540

Ic × Length (A-m)Minimum Ic (A/cm) @ 0.2 μV/cmLength (m)


Aug. 2008: Ic > 300 A/cm achieved over 600 m

190,260302630181,980337540

Ic × Length (A-m)Minimum Ic (A/cm) (0.2 μV/cm)

Length (m)

0

50

100

150

200

250

300

350

400

450

0 100 200 300 400 500 600

Position (m)

Ic (A

/cm

)

77 K, Ic measured every 5 m using continuous dc currents over entire tape width of 12 mm (not slit)

Voltage criterion = 0.2 microvolt/cm Except for four spots, Ic of rest of 630 m > 350 A/cm


10

100

1,000

10,000

100,000

1,000,000

May

-02

Oct

-02

Mar

-03

Aug

-03

Jan-

04Ju

n-04

Nov

-04

Apr

-05

Sep

-05

Feb-

06Ju

l-06

Nov

-06

Apr

-07

Sep

-07

Feb-

08Ju

l-08

Crit

ical

Cur

rent

* Le

ngth

(A-m

)

Remarkable progress in 2G HTS wire scale-up over the last 6 years

0

40,000

80,000

120,000

160,000

200,000

240,000

Nov

-01

Jul-0

2

Mar

-03

Nov

-03

Aug

-04

Apr

-05

Dec

-05

Aug

-06

Apr

-07

Jan-

08

Sep

-08

Crit

ical

Cur

rent

* Le

ngth

(A-m

)

62 m18 m1 m 97 m

206 m

1 m to 1,300 m in 6 years

158 m

322 m427 m

595 m

World Records

790 m

1,311 m

935 m

Growth in last year


Great strides made in 2008 in all key metrics

30%0.950.73Coil: Field at 77 K (T)

212%630202103Length with Ic > 300 A/cm (m)

98%337170Ic over 500 m (A/cm)

88%340181Ic (A/cm) at 65 K, 3 T

97%229116Ic (A/cm) at 77 K, 1 T

220%1030322322Length with Ic > 200 A/cm (m)

39%40651002G Wire Price ($/m)

233,810

1,311

378*

813

ISS 2008

120%595322Completed 2G wire Piece Length (m)

37%595470Ic (A/cm) over 1 m

102,935

227*

ISS 2007

127%

67%

Improvementin past year

246Ic over 200 m (A/cm)

70,520Ic × L (A-m)

ISS 2006Metric

*at 100 to 200% higher speed than in 2006


0

20

40

60

80

100

120

140

160

180

0 100 200 300 400 500 600 700 800 900 1000 1100 1200Position (m)

Ic (A

)Location of joints

Per customer’s requirement, 1200 m long wire was produced with 11 splices in a production operation. Arrangement of the 12 segments along the length was decided based on communication with customer so that the Ic profile would fit the coil winding requirements

Development of Practical Conductors - Joints


Excellent resistance measured in all joints and mechanical robustness also demonstrated

All but one of the joints showed resistance around 33 nΩ, One joint showed a resistance of 100 nΩ, still within limit

-1.00E-05

0.00E+00

1.00E-05

2.00E-05

3.00E-05

4.00E-05

5.00E-05

6.00E-05

0 20 40 60 80 100 120 140

Current (A)

Volta

ge (V

olt)

Joint#1: 70-75mJoint#2: 175-180mJoint#3: 250-255 mJoint#4: 350-355mJoint#5: 440-445mJoint#6: 560-565mJoint#7: 670-675mJoint#8: 760-765mJoint#9: 890-895mJoint#10: 980-985mJoint#11: 1120-1125m

1.00E-05

1.50E-05

2.00E-05

2.50E-05

3.00E-05

3.50E-05

4.00E-05

0 20 40 60 80Current (A)

Volta

ge (V

olt)

1st test

After running thru 4" roller 3 times

After running thru 2" rollers 6 times

Wires with joints have to run through the reel-to-reel Ic test rig with 4” and 2”roller. No trace of degradation was shown in I-V curves


Continuous multifilamentary 2G wire is now scaled to 15m lengths with new industrial process

4 mm

• Good Ic and reasonable ac loss reduction achieved;

• Coils were made with long length multifilamentary wires, showed lowered ac loss in magnetic field and with transport ac current as reported at DOE Peer Review (July 2008)

0.00 0.01 0.02 0.03 0.04 0.05 0.060

1

2

ac lo

ss (

W/m

)

Bac rms (T)

5.1 x

100 Hz unstriated

multifilamentary


Customer-driven development of insulated wire

• Preliminary test showed no breakdown at 1000 V with 0.0025 mm polyimide film• Deliveries of insulated wire already being made.

• Several customers, primarily for coil applications, required insulated 2G wire• After evaluating a number of vendors, we procured a system for in-house

fabrication of insulated wire• System in place and being used for both 12 and 4 mm wide wire

1. AC Loss Characterization of HTS Coils

2. Proposed Integrated Cryo-cooled Test Bed for High Power Density Power System Components

Florida State UniversityCenter for Advanced Power Systems

Tallahassee

Sastry Pamidi

AC Losses With Liquid Nitrogen Boil-off Measurements

Useful for Total AC loss measurements on coils up to 140 mm in diameter and 250 mm tall.

Wide measurement range: fraction of a watt to 100 W

Coils can be arranged in any orientation with respect to magnetic field

Magnetic field amplitude: up to 200 mT

Transport current amplitude: up to 650 A

AC Losses in YBCO Coils with Nitrogen Boil-off Technique

Calibration Highly Reproducible

Sample Coil

Calibration Heater

Diameter - 145 mmLength - 250 mm

B

System has been tested and calibrated up to 60 W, 150 mT, 200 Hz

YBCO Coils, 29 turns, of wire ~4.5 m conductor 45 mm diameter, Ic = 32-34 A

Losses are < 0.1 W in parallel and perpendicular field 150 mT, 55 Hz & 60 mT, 200 Hz

AC Losses in YBCO Coils with Nitrogen Boil-off Technique

Super Power Coil Losses < 0.1 W

@ 150 mT, 55 Hz &60 mT, 200 Hz

Two coils were tested –Coil made of normal YBCO tape and Coil made of Striated YBCO ( five filaments). Both have < 0.1 W losses. 0.1 W is minimum detectable limit of the measurement system

Address system issues arising from the complex interrelationships between the electrical, thermal and material performance characteristic to achieve high power density systems through cryo-cooling.

Design and manufacture a 400 kVA, 13,8 kV HTS transformer for application in Test loop

Design and manufacture a +/- 5 kV MVDC HTS cable

Objectives of the Proposed Integrated Cryogenic System for Multiple High Density Power System Components

Flow sensors

Cryo booster

Temp sensors

Valves

Blowers

Electrical bushing

A Schematic of the Proposed Integrated Cryogenic System for Multiple High Density Power System Components

HTS AC/DC Cable

Main Cryostation HTS

Transformer

Capacitor Bank

HTS faultCurrent limiter

AC/DC

Converter

Load

Bank

Proposed Applications of Cryo-cooled Test Bed

Understanding of cryogenic system integration issues

For external users to test high density power devices

Comprehensive test environment with PHIL testing and heat loads and thermal gradients under test conditions

Demonstrate integrated high power density electrical network

1

Proposal of

9th Annual EPRI Superconductivity Conference

In Korea

2

Date From 9th Nov.(Monday) to 11th Nov.(Wednesday)

HostEPRI, KEPCO(KEPRI), and KIASC

* KIASC : Korea Institute of Applied Superconductivity and Cryogenics

Program

Committee

International Program Committee ;

• EPRI, KEPRI, KIASC

Local Program Committee ;

• KERPI, KIASC, KERI, LSC, KIMM, etc.

Conference

Site

KEPRI in Daejeon Korea (2 days)

Accommodation : Yusung Hotel, Rivera Hotel etc

Technical Tour : Gochang Test Field (1 day)

LS Cable Factory Tour (1day) : option

Outline Outline

3

Nov. 2008First Announcement(9th Annul EPRI Superconductivity Conference)

Feb. 2009 Website Opens

Aug. 2009 On-Line Submission of Abstracts

Sept. 2009 Abstract Acceptance & On-line Registration

Oct. 2009 Last Announcement with Final Program

Nov. 2009 Conference

Schedule (Tentative)Schedule (Tentative)

4

Conference Schedule (Tentative)Conference Schedule (Tentative)

First day ( KEPRI in Daejeon)

Registration

Presentation

Welcome Party and Dinner

Second day

Presentation

KEPRI Superconducting Lab Tour in KEPRI

Third day (Technical Tour : Gochang Test Field)

Move : Daejeon -> Gochang (by Bus)

Test Field Tour including 22.9kV and 154kV superconducting cable

Excursion : Sunwonsa Temple

4th Day (Option) : LS Cable Factory Tour

5

What benefit will you get ?

• You can contact with many experts from oversea

• You can get the current information on Superconductivity

System more broadly including Asia

• You can see the overall of the Superconductivity System. For

Example, HTS Cable, SFCL, Flywheel developed by Korea

• You can look around Gochang Test Center, specially new

underground test lab that is the biggest one in the world

through technical tour

• Lastly, you can enjoy beautiful sightseeing that may be great

mountain covered with colorful tree at Autumn

6

Technical TourTechnical Tour

Seoul

Busan

Daejeon

Gochang

7

Seoul

Busan

Daejeon

8

Testing Facility for HTS Cable by KEPCO

Place : Gochang Testing Center

Start : 2008.3

Finish : 2009.9

• 154kV Superconducting Cable Test will start 2009.6

9

KEPRI in Autumn KEPRI in Autumn –– Conference siteConference site

10

NaejangsanNaejangsan national Parknational Park

11

SunWonSaSunWonSa TempleTemple

High Opportunity Commercial Applications for HTS Cables

Eighth Annual EPRI Superconductivity ConferenceOak Ridge, TN ~ November 12 – 13, 2008

IntroductionIntroduction

• The scope and successful operation of recent HTS cable projects has led to:• Increased interest in HTS cables • Increased interest in their characteristics • Increased interest in possible applications

• Superconductor Cables are an Exciting New Tool for Utility Planning Departments, but requires:• Education on their benefits and applications• Education on what is involved to install and operate

• Agenda• Review of HTS cable applications which appear to be of

greatest interest during educational presentations • Issues moving forward

Key HTS Cable ELECTRICAL CharacteristicsKey HTS Cable ELECTRICAL Characteristics

• Very high power transfer capability compared to conventional cables solves many siting problems

• Very low impedance reduces loading on parallel lines and equipment

• Minimal magnetic field and elimination of heatsimplifies placement concerns and is easy on the environment

• Optional HTS cables with fault current managementcapabilities eliminate need to upgrade existing equipment

HTS Cables offer unique capabilities

Power Transfer Equivalency of HTS CablesPower Transfer Equivalency of HTS Cables

HTS Cables provide much greater power transfer than conventional cable

0 200 400 600 800 1000

13.8 kV

34.5KV

69kV

138kV

230kV345kV

Power Transfer Capability - 3Ø MVA

100 MVA at 13.8 kVXLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

HTS

HTS

HTS

HTS

* No XLPE cable de-rating factors applied. HTS rating based on conventional 4000A breaker rating

• Same Voltage, More Power• Greatly increased

power transfer capacity at any voltage level

• Same Voltage, More Power• Greatly increased

power transfer capacity at any voltage level

• Same Power, Lower Voltage• New MV versus HV

Siting Opportunity• “MV Transmission”• Ideal for NIMBY &

ROW sparse environments

HTS Cables provides transmission-level power transfer at medium voltage

0 200 400 600 800 1000

13.8 kV

34.5KV

69kV

138kV

230kV345kV


XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

HTS

HTS

HTS

HTS

* No XLPE cable de-rating factors applied. HTS rating based on conventional 4000A breaker rating

0 200 400 600 800 1000

13.8 kV

34.5KV

69kV

138kV

230kV345kV


XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

XLPE Cable

HTS

HTS

HTS

HTS

Power Transfer Equivalency of HTS CablesPower Transfer Equivalency of HTS Cables

Project HYDRA OverviewProject HYDRA Overview

Current ConEd System Configuration

ConEd’s System of the Future:• Interconnected Distribution Substations

• Integral Fault Current Limiting

Copper power cables HTS power cables

DHS Project supports development of a more resilient grid with increased reliability and reduced power outages

Paralleling Urban Buses Paralleling Urban Buses ––Building on Project HYDRA Building on Project HYDRA

• “Virtual Bus” must Handle high power flow between the substations• Conventional interconnection techniques not practical• Normal impedance during steady state operation would limit power transfer • Multiple cable circuits would be required

VIRTUAL BUSConnection

Paralleling low-side buses with conventional technologyis not practical

Typical 2-transformer urban substations

Paralleling Urban Buses: HTS SolutionParalleling Urban Buses: HTS Solution

HTS Cable Advantages• Low impedance allows for efficient power transfer• Ampacity of HTS cable capacity requires only one circuit

• e.g. 100MVA at 15kV• Reduced external EMF and heat generation simplifies placement

4000A

HTS Cable Enables Low Side Interconnection

Load Current


Paralleling Urban Buses:Paralleling Urban Buses:Addressing Fault CurrentsAddressing Fault Currents

Fault Current Limiting HTS Cable provides many benefits:• Reduces the fault current that flows through the HTS cable• Reduces fault current contribution to faults on either substation bus• Eliminates need to replace or upgrade station equipment

60,000A

Fault Current Limiting HTS Cable makes low side networking practical

Fault CurrentContribution

30,000AReduced Fault CurrentContribution

With Fault Current Limiting HTS Cable


Paralleling Urban Buses: Paralleling Urban Buses: The AppealThe Appeal

Advantages of Paralleled Substations – Simple Case• Connect additional load without additional transformers or new substations• Increases transformer asset utilization• Reduces cost of N-1 contingency planning; Only 1 transformer required

versus 2• Increased interconnectivity protects vulnerable, critical loads in the event of

a catastrophic failure


Paralleling Dense Urban Load Centers Leads to Operational Efficiencies

Total Load ≤60% total transformer MVA Total Load ≤60% total transformer MVATypicalLoadingPractice

Paralleling Urban BusesParalleling Urban BusesIncreased Asset UtilizationIncreased Asset Utilization

Transformer Asset Utilization TS Inteconnected Substations; n-2 Criteria

30%

40%

50%

60%

70%

80%

90%

100%

None 2 3 4 5Number of Interconnected Substations

Tran

sfor

mer

Ass

et

Util

izat

ion

3 XFRMR4 XFRMR5 XFRMR

Interconnecting Substations increases transformer asset utilization*• Improves financial performance measures• Reduces the number of transformers required to serve load

* Theoretical limits

Transformer Asset Utilization TS Inteconnected Substations; n-1 Criteria

30%

40%

50%

60%

70%

80%

90%

100%

None 2 3 4 5Number of Interconnected Substations

Tran

sfor

mer

Ass

et

Util

izat

ion

2 XFRMR3 XFRMR4 XFRMR5 XFRMR

Paralleling Urban BusesParalleling Urban BusesServing Additional LoadServing Additional Load

HTS Interconnected Substation Loading Increase Capability; n-2 Criteria

0%

20%

40%

60%

80%

100%

120%

140%

160%

180%

2 3 4 5Number of Interconnected Substations

% In

crea

sed

Load

C

apab

ility

3 XFRMR4 XFRMR5 XFRMR

Interconnecting Substations significantly increases load serving capability*• Significantly reduces need to expand or build new substations

* Theoretical limits

HTS Interconnected Substation Loading Increase Capability; n-1 Criteria

0%10%20%30%40%50%60%70%80%90%

100%

2 3 4 5Number of Interconnected Substations

% In

crea

sed

Load

C

apab

ility

2 XFRMR3 XFRMR4 XFRMR5 XFRMR

Segregated (Remote) SubstationSegregated (Remote) Substation

• Smaller, remotely located, lower voltage switching station in space or real-estate constrained location

HTS CABLE

• Larger, HV station components located where space is available

• MV HTS cable acts as low impedance, high capacity, virtual bus between transformer and switching stations

• Reuse existing ROW• Simplified placement due to lower

voltage level• FCL HTS cable may reduce MV

breaker requirements

Permits new substation construction in spite of severe real estate constraints

Segregated (Remote) SubstationSegregated (Remote) Substation

HTS CABLE

HTS Cables can be consistent with tradition reliability design practices

HTS CABLE

• Multiple HV stations located where space is available to provide for contingency planning

• MV HTS cables provide links and fault current control

Overcoming Transmission Line Overcoming Transmission Line Siting DilemmasSiting Dilemmas

HTS Cables Very Attractive to Address Transmission Siting Issues

• Underground construction• Preferred by the public• Better storm performance• HTS offers simplified

burial requirements• Space efficient

• Lower voltage option simplifies siting

• Environmental benefits• No EMF emissions • Environmentally friendly

insulation system• Positive public relations

Power system reliability and load growth requires new interconnections to strengthen the grid and supply new load

GG

GG

Substation A Substation B

Simplifying Transmission SitingSimplifying Transmission Siting

HTS Cables Offer New Options to Siting Power LinesPhoto courtesy Consolidated Edison

One MV HTS Cable can replace:• Many conventional underground

circuits• Overhead transmission line

One MV HTS Cable can replace:• Many conventional underground

circuits• Overhead transmission line

Connecting Generating Stations to GridConnecting Generating Stations to Gridor Any Short, High Power Linkor Any Short, High Power Link

HTS Section for sensitiveor ROW restricted areas

G

G

G

G

HTS Cables Can Ease or Eliminate or Simplify Short Link Issues

GenerationStation

Grid PCC

• Advantageous for short, high power transfer situations• Permits use of more compact, easier to site, lower voltages• Environmentally and politically preferable underground

construction• Lower losses

• Ideal for routes including sensitive or ROW restricted areas

Conventional constructionfor balance of link

Grid CongestionGrid Congestion

Line loading, equipment & operational limitations can lead to grid congestion

Grid Congestion has many causes• Insufficient line ampacity• Overloaded critical assets and

circuits• Undesired loop flows• Stability issues

GG

UndesiredLoopFlow

GGGenerationGeneration

LoadLoad

Load Current

Load Current

HTS Cable Can Alleviate Grid CongestionHTS Cable Can Alleviate Grid Congestion

• During normal operating conditions, the HTS cable is a low impedance pathand allows for the transfer of large amounts of power.

HTS CableHigh Normal Current

Low Fault Current

Numerous benefits accrue:• Increased corridor transfer capability of the corridor• Reduced loading on parallel circuits• Improved efficiency from lower I2R losses on all lines

GG

Load Current

GGGeneration

Load

Load Current

Load Current

Reduced line

losses

Increased line

loading

Reduced loading

on assets

During Faults HTS Cable Limits Fault CurrentsDuring Faults HTS Cable Limits Fault Currents

• When an HTS cable with resistive FCL capability becomes resistive during a fault, the fault current must use relatively lower impedance paths

HTS CableHigh Normal Current

Low Fault Current

The HTS cable results in higher system impedance during faulted conditions lowering overall fault current magnitudes

GGFaultFault

Fault Current

FaultCurrent

GGGenerationGeneration

Increased Fault impedance increases

total circuit fault impedance

Conventional Vs. Project Hydra Style HTS CableConventional Vs. Project Hydra Style HTS Cable

ScenarioMVA Transfer

Capacity Increase Sub#1 Sub #2

Base Case 230 MVA Base 42 kA 56 kA

2nd Conventional Cable +230 + 5 +2

Replacement HTS Cable +248 -12 -3

Fault Current Level Change (kA)

Installing HTS Cable in the grid simultaneously can increase power transfer capability and manages fault current levels

SummarySummary

• HTS Cable Systems offer solutionsunavailable or impractical until now

• As utilities are exposed to HTS cableconcepts, applications become apparent

• Most utility personnel have had little exposure to HTS cables andtheir characteristics

• This exposure is for the most part limited to a utility’s advanced technology or R&D functions• i.e., those that are exposed to normal planning issues are not

considering HTS solutions• The industry must undertake an Educational Awareness program to

ensure HTS cables become part of the engineer’s toolset

•HTS cable applications are nascent•Education is required to spur demand

Portions reprinted, with permission, from Massachusetts Institute of Technology and Joseph Minervini.

Technology & Engineering Division

Development of HTS Cables for DC Power Transmission and Distribution

Joseph V. MinerviniLeslie Bromberg

Makoto TakayasuChristopher Miles and Nicholas R. LaBounty

MIT Plasma Science and Fusion Center

Eighth Annual EPRI Superconductivity ConferenceDoubletree, Oak Ridge, TN ~ November 12 – 13, 2008


Technology & Engineering DivisionOutline

• HTS DC Advantages• Cable Design Concepts• Chubu-MIT HTS DC Cable Collaboration• Long Length Cooling• Current Lead Cooling• Potential Near Term Application• Conclusions


Technology & Engineering DivisionDC Superconducting Transmission Line

Advantages:•No DC resistive losses•No AC inductive storage•Low or no AC losses•Long range transmission of high currents, including undersea•Very high power ratings including transmission of several GVA •Fault currents limited by fast acting inverters at AC/DC and DC/AC ends of the line•Low voltage transmission, if desired, limiting the need for high voltage transformers•Simplified cable design, more amenable to using HTS tape geometry•Cable coolant also used to cool solid state inverters increasing capacity and reducing high temperature aging degradation

Disadvantages: Invertors can add substantially to cost



HTS DC increases efficiency for long distance transmission Opens other advanced technology opportunities:

• Direct connection of alternative low-carbon or carbon-free power sources:WindSolar PVFuel CellMicroturbineother

• Connection of advanced energy storage devicesFlywheelBatterySupercapacitorSuperconducting Magnetic Energy Storage (SMES)other

HTS DC Applications

Grid independence

System Stability and Power Quality



HTS DC Transmission Cables

DC-to-AC Power Conversion

Off-Shore Wind Farm Power Transmission

Using HTS DC Cable



Solar Photovolatic or Concentrated Solar Thermal Power Transmission Using HTS DC Cable

Solar PV CSP

Solar and WindDC Power

Transmit DC before conversion?

DC Superconducting Power Transmission Line Experiment in

Chubu University&

Collaboration with MIT

Prof. Satarou YamaguchiDept. of Electrical Engineering

[email protected]

Center of Applied Superconductivity and Sustainable Energy Research

(CASER)

Experimental Device in Chubu University

Parameterscurrent > 2.5 kAvoltage > 20 kVlength ~ 20 mSumitomo Bi-2223 cable

coolant; LN2equipped with pump and cryogenic cooler72 K - 77 K

SC Cable

made by Sumitomo

insulation layer

HTS Tape

formercopper wires

inner spring

center holefor coolant path

Photo of cross-section

40φ

insulation30kVDC

earth layer

formercopper wires

HTS Tape x 39

Side View

Tape conductor 1st layer; 192nd layer; 20

Bi-2223/ 100A grade

Insulation Volt. DC20kV Insulator, PPPL

Outer radius 40φ Center hole 14φ


Technology & Engineering DivisionMIT High Current HTS

DC Cable Designs

Multiple Layers

Triplet

Carpet Stack

Twisted Triplets

Wedge Stack

Twisted Triplets



• Use Basic Carpet Stack– tapes can be insulated or soldered• Square or rectangular stack • Base element former can be– conducting– non-conducting– Structural• Tape shape requires relatively long twist

pitches• AC losses not an issue for DC applications



• 25 kA at T = 65 K - 77 K• Carpet Stack triplets have highest Je• Allows for smaller cryostat and lower heat leak• Carpet Stack and wedge base conductors allow many

variations on cable patterns and total tape number


Technology & Engineering Division Potential OpportunityData Server Centers

• In 2006, electricity consumed by servers in U.S. data centers (including cooling and auxiliary infrastructure) represented about 1.5 percent of national electricity use*.

• Internet data center consumes ~ 1–2 kW/m2.– 10 MW-50 MW+ total capacity in new centers

• DC may be preferred– Minimizes conversion losses

• ~7-10% energy savings migrating to DC– No reactive power– Power multiplier: for 1 W dissipation saved, 1.5 - 2 W

cooling eliminated

Google datacenter near The Dalles Dam

*”Report to Congress on Server and Data Center Energy Efficiency”, U.S. Environmental Protection

Agency, Aug. 2, 2007



Expected Data Server CenterPower Growth

G. Lawton, Powering Down the Computing Infrastructure, Computer, IEEE, 40, issue 2, p 16-19, Feb. 2007.

DC Distribution Demonstration Developed by LBNL and Industry Partners

William Tschudi, LBNL

Measured Best in Class AC System Loss Compared to DC• ~9-12% efficiency improvement measured by elimination of transformer

and second AC/DC conversion

PSU

ASD

Ballast

AC Distribution

Electronicloads

Lightingloads

Motorloads

AC/DC

AC/DC

VRAC/DCDC/DCAC/DC DC/AC

DC/AC

DC/AC

60 Hz AC480V

AC/DC DC/AC

DC/ACDC

300-400V

PV

FC

Benefits of 400Vdc

Slides courtesy of Annabelle Pratt-Intel

PSU

ASD

Ballast

Facility Level

Electronicloads

Lightingloads

Motorloads

AC/DC

AC/DC

VRAC/DCDC/DCAC/DC DC/AC

DC/AC

DC/AC

60 Hz AC480V

AC/DC DC/AC

DC/ACDC

300-400V

PV

FC

Benefits of 400Vdc


XX

XXXX

XXXX XX

XX

XX

ASD

PSU

Ballast

400V DC facility with DG

60 Hz AC480V

Electronicloads

Lightingloads

Motorloads

VRDC/DC

AC/DC

DC300-400V

DC/AC

DC/AC

Benefits of 400Vdc

AC/DC

DC/DC

DC/DC


ASD

PSU

Ballast

400V DC facility with SC Bus

60 Hz AC480V

Electronicloads

Lightingloads

Motorloads

VRDC/DC

AC/DC

DC300-400V

DC/AC

DC/AC

Benefits of 400Vdc

AC/DC

DC/DC

DC/DC



Technology & Engineering Division 4400 Ampere Cable Sizes

1.75” Diameter cable325 A per cable

14 Cables35 lbs/ft

0.605” Diameter cable133 A per cable

33 Cables8 lbs/ft

1.75” Diameterup to 30 Conductors

up to 200 Amps per Conductor1 Cable2.0 lbs/ft

Copper - Air cooled Copper - Water cooled HTS- LN2 Cooled

Very High Power Density is Achievable with Superconductors

x 10 = 4000 A @ 0 Voltage ®



Schematic 10MW, 400V, 25 kAData Center Layout



Technology Needed to ImplementSC Distribution

• As opposed to transmission, there are a large number of secondary spurs, with relatively high density (depending on application)

• Refrigeration losses dominated by leads, not by distributed cryostat or AC losses

• Need to address the problem of– Electrical connections through low-loss leads– Cooling manifolding



Navigant Consulting costing predictions of SC components in 2008-2012:http://www.energetics.com/meetings/supercon06/pdfs/Plenary/07_Navigant_HTS_Market_Readiness_Study.pdf

Power Dissipation with Standard Leads (kW)

Summary of Preliminary System AnalysisMIT Energy Initiative Seed Fund - 2008

Current lead loss is 0.05 W/A-lead

Power Loss HTS + Cu

(2007)

Power Loss HTS + Cu (2008-2011)


Power Loss All Cu

HTS Leads 10 10 10

HTS Cryostat 0.45 0.225 0.225

HTS Cold Power Total 10.450 10.225 10.225

Refrigerator Wall Power 300 177 118

Copper Bus 16 16 16 250

Total Electrical System Power 316 193 134 250



Navigant Consulting costing predictions of SC components in 2008-2012:http://www.energetics.com/meetings/supercon06/pdfs/Plenary/07_Navigant_HTS_Market_Readiness_Study.pdf

Power Dissipation with Optimized Leads (kW)

MITEI Seed Fund Study (cont’d)

Current lead loss is 0.025 W/A-lead achieved by intermediate cooling stage

Power Loss HTS + Cu

(2007)



Power Loss All Cu System

HTS Leads 5 5 5

HTS Cryostat 0.450 0.225 0.225

HTS Cold Power Total 5.450 5.225 5.225

Refrigerator Wall Power 157 90 60

Copper Bus 16 16 16 250

Total Electrical System Power 173 106 76 250



Navigant Consulting costing predictions of SC components in 2008-2012: http://www.energetics.com/meetings/supercon06/pdfs/Plenary/07_Navigant_HTS_Market_Readiness_Study.pdf

Capital Costs (k$)


Capital Costs HTS + Cu

2007

Capital Costs HTS + Cu 2008-2011

Capital Costs HTS + Cu 2012-2016

Capital Costs All Cu

HTS Tape 2,800 560 112

HTS Cryostat 200 130 44

HTS Refrigerator

1,050 640 260

HTS Total 4,050 1,330 416

Copper Bus 11 11 11 160

Total Capital Cost

4,061 1,341 427 160



Operating Costs of Power ($/Hr)

Electricity cost = $0.10/kW-Hr


Operating Costs 2007

Operating Costs

2008-2011

Operating Costs

2012-2016

HTS (standard leads) 31.69 19.27 13.38

HTS (optimized leads) 17.26 10.62 7.61

All Copper 25.07 25.07 25.07

HTS Payback Period (standard leads)

Never 23 Years 2.6 Years

HTS Payback Period (optimized leads)

57 Years 9.2 Years 1.75 Years


Technology & Engineering Division Summary

Use of HTS could open innovative opportunities in datacenters for decreased power consumption, flexibility and easy of constructionApplication to data server centers is a near term application with potential large efficiency gainsShort time scale implementation allows further development for other MicroGrid applications with similar technologyEstablishes technology for:

• Bringing large-scale power to land from offshore wind farms

• Combining large-scale solar PV or solar thermal systems to the grid

• Long distance power transmission and/or grid interconnects

Optimized DC cable, cryostat and current leads require development program

A High-Power Superconducting DC Cable

W. V. Hassenzahl

Eighth Annual EPRI Superconductivity Conference

11/13/2008

Outline

• The team• Visions Past and Present• Why a superconducting DC cable• Program goals• Design concept• Design process

11/13/08 2An SC-DC Cable

The team

• Steve Eckroad• Bill Hassenzahl• Paul Grant• Brian Gregory• Stig Nilsson


Why a SC DC Cable

• High Power Capacity pluses and minuses• Negligible losses resistive and AC • Physical Dimensions Small vs. Power Lines• Security • High Current and Relatively Low Voltage• Reliability• Versatility• Efficiency Lower Life Cycle Cost


Why operate near 77 K?• To answer this question we need to explore conductor costs and the

life cycle energy demands of an installed cable


Why operate near 77 K?• To answer this question we need to explore conductor costs and the

life cycle energy demands of an installed cable


CautionComparisons aremodel specific.

Why A DC Cable near 77K?• 77 K a real sweet spot


Program Goals• Design a Superconducting DC Cable System that

meets future utility needs and requirements.– Recognize high power limitations of local AC system– Assess power levels and cable lengths– Note power independent costs of proposed design

• Use existing engineering capability for materials and fabrication processes.

– Structural Materials– Cryogenics and vacuum– Power Converters– Superconductors

• Not the driver!


2 SC DC Cable Systems• Assessed power levels and cable lengths

– Selected two cable systems for Reference Designs• Regional 2 GW <300 km• Inter regional 10 GW >500 km

– Established a simple set of design requirements • multiple power feeds and loads• redundant cables in each circuit• redundant converters

• Iterative Process– Power Levels, Ranges, and Limits I and V– Conductors, other materials, standard practices

Metal Sheath OD and Vacuum shell piece length – Metal Sheath OD and Spool Sizes

Cable section lengths, i.e., Unit length between joints– Heat loads Cryogenic Requirements

Fluid Flow Area Cryogenic Diameter and stop joint– Vacuum requirement Outer Shell ID


Power Ranges - I and V

• Regional 2 GW1 GW per SCDC CableEach cable has full capacity for redundancy ~33.3 kA and ~60 kV*

• Inter Regional– up to 10 GWE.g., power farm to major loads

5 GW per HVDC CableEach cable has full capacity for redundancy ~100 kA and ~100 kV

* May choose 100 kV


Design Concept • Details of cross section

depend on operational conditions

• Figure includes recent changes to accommodate ground issues raised by AC/DC Integration team

• Approximate diameter 12 cm


Cable Section Length

• V, I, and material properties determine – Metal Sheath OD– Cable weight per meter of length– Note mechanical properties of insulation require a

larger minimum thickness than does voltage standoff• Metal Sheath OD, spool dimensions, and required

pulling force determine– cable section length from spreadsheet

• Manhole or other access capability required at end of each section for joint preparation

• Experience with conventional cables is applicable


Heat Loads

• Heat sources– Conduction– Convection– Radiation– AC losses = hysteresis from current changes and ripple– Cable ends / joints– Cryogen flow losses

• Use nominal heat load of 1 W/m for initial calculations.


AC Losses• Two types of heat input in the superconductor

– Current ramping and faults– Harmonic currents

• Several methods for calculating heat input.– Abrupt current decrease can only deliver energy

associated with inductance per unit length L/l• Energy goes into enthalpy of nitrogen ΔT<0.01K

– Harmonic currents set limits on converter design and operation

∑ ⋅⋅≅ −

n_all

2nn

7 I104)m/W(P ω


Vacuum • Conduction and convection heat load must be < 0.5 W/m

depends on use of mli and quality of vacuum• Required vacuum about 2x10-4 Torr

– First approach permanently sealed system with getters• Not feasible to guarantee >500 km without leaks.

– Second approach vacuum pumps at fixed spacing• Issue is pressure increase from pump to furthest point requires

large open cross section• Calculation of spacing is based on gas flow from largest leak,

conductance of the cable vacuum space, and vacuum pump capacity.• Determine that a 0.7 m pipe, 50 liter/s, 10-4 Torr vacuum pumps

with every km will meet vacuum needs even if some pumps fail.• Pumps need not work full time after operation begins• Also, pumps must be able to pump down the cable prior to use

Pump spacing is intimately connected with maximum cable piece length11/13/08 15An SC-DC Cable

Cryogenics• Superconductivity requires a low temperature

– 65 to 70 K for liquid nitrogen– Over distances of a 1000 km– Small temperature variations

• Normal operation ± ~ 1 K• Upset/fault conditions > +5 K

• Requires pressurized flow of liquid nitrogen– Pressure of several atm required to limit bubble formation

and to maintain consistent dielectric strength– This “low” pressure allows the use of thin walled pipes– Which, in turn, limits the allowable pressure rise caused by

flow resistance


Cryogenics• Refrigerator loads and separation

– Choice of capacity of each refrigerator depends on• Total heat inflow between refrigerators• Need for on line maintenance• Operation during and after upset/fault conditions• Cool down• Cost vs. capacity factors (Optimization for the future)• Iterative process among heat load, refrigerator spacing, reliability, etc.

– A pressure rise of 2.5 atm. is allowable for an operating pressure of 5 to 10 atm.

– A flow rate of 5 liters/s can remove 10 kW– The associated pressure rise in 10 km is ~3 atm, 45 psi.– Choose 5 to 10 km refrigeration spacing.


The grid should not know about refrigerators

Pumping/friction power is about 0.2 W/m

Cryogenics Summary

• Heat load, allowable temperature rise determine– Minimum cryogen mass flow

• Cryogen mass flow and allowable pressure drop determine

– total refrigerator capacity and refrigerator spacing.• Refrigerator spacing is an optimization issue.

– 5 to 10 km is adequate with a 3 to 5 atmosphere pressure drop for liquid nitrogen.

Part of iterative design, but not a driver


Design Concept


Factory Assembly

• Outer pipe– Standard high pressure gas pipe– Special welding and cleaning– Reflecting surface on inner diameter– Environmental protective outer coating – Piece length determined by shipping constraints (?~20 m)

• Cryogenic pipe and cryogen return pipe– Corrugated stainless steel– Special weld requirements– Supported at each end from outer pipe

• Superinsulation– Most important 30 to 50 layers between outer pipe and

cryogenic components– A few layers between the two cold pipes.


Pipe Section and Transport


On Site Assembly


This procedure is followed for some 50 sections

Vault and Cable Pulling


Joints


Joints• Cable joint Issues

– Large number of superconductor tapes/wires– Field procedures especially repairs– End connections and terminations

• Pipe joint characteristics determined by – Manufacturability– Cleanliness– Superinsulation protection– Accommodation of cable pulling loads– Thermal contraction associated with cooldown


Cable Installed


Cryogenic Vault


Outer Pipe Summary• Outer pipe diameter >70 cm determined by

– Cryogen pipe diameter– Vacuum pressure drop– Vacuum pumping requirements with redundancy

• Outer pipe piece length determined by transportability ~ 20 m maybe 30 m max

– Fabricate in plant with mli and cryogen tube • Includes supports for axial and radial motion of cold

components• Seal in factory for cleanliness

• Assemble (weld) pipes and cryogen tubes on site and pull cable from ends.


Gas Pipeline


SC-DC Cable Program Status

• Critical issues for future evaluation– Cable piece length – Power converter and grid interface– Other existing and new superconductors– 100 kA joints– Temperature optimization– Allowable heat loads– Vacuum requirements– Details of refrigerator mechanical interface to cable– Overall cost evaluation


1

Power Flow and Transient Stability Impacts of

Superconducting DC CablesTom Overbye

University of Illinois and PowerWorld Corporation

Eighth EPRI Superconductivity ConferenceNovember 12-13, 2008

This presentation is based on work is being performed under contract with EPRI

Overview

• Goal of this work is to consider the power flow and transient stability impacts of integrating a multi-tap, superconducting DC (SCDC) cable system within the Eastern Interconnect and within the WECC system.– Power levels are up to 10 GW

• A dual SCDC cable system is assumed, with the ability to failover with full power in the event of a fault on one of the cables. – Analysis compared different failover scenarios with

remaining cable ramping to full power over a few seconds– After failover full power is assumed on the remaining cable

Eastern Interconnect Study System

• The system studied was the NERC/MMWG 2008 summer peak case from the 2006 series.

• Case has 48,370 buses, 7397 generators, a total load of 660 GW and total generation of 676 GW.

• 2006 series dynamic models.• Power flow and transient stability runs were done

using PowerWorld Simulator version 14.• As is common with the MMWG cases, there were

many initial line violations (330 lines at >= 100% of A limit MVA, 95 lines >= 120% of A limit MVA)

Eastern Interconnect Route for 10 GW Cable System with Six Stations

2000 MW

2500 MW

2000 MW

1500 MW

2000 MW

10,000 MW of Asynchronous Generation

System Modifications

• System was modified to include the SCDC cable system by adding five new buses (100001 to 100005) with their generation set to match SCDC cable injections. Buses were then connected to existing buses by short lines:– Bus 100001 to 36260 (2.5 GW) Chicago South– Bus 100002 to 36421 (2.0 GW) Chicago North– Bus 100003 to 31230 (2.0 GW) St. Louis– Bus 100004 to 57968 (1.5 GW) Kansas City– Bus 100005 to 54901 (2.0 GW) Oklahoma City

• The remote source generator(s) was assumed to be operating asynchronous with the rest of the grid.

System Modifications, cont.

• Existing generation in areas with SCDC cable injections was reduced to satisfy area ACE requirements.

• Once the SCDC cable injections were modeled, two new 345 kV lines needed to be added to reduce line loadings.– Between buses 57977 57968 (South of Kansas City)– Between buses 57968 59200 (South of Kansas City)

• System with SCDC cable was not augmented to make it n-1 secure, but there were no significant base case violations.

Example: Original Kansas City Area Flows and Voltages

Kansas City Area Flows and Voltages with SCDC Cable

Power Flow Conclusions

• Integration of the SCDC cable within the existing system will require modifications to the transmission grid similar to those needed to accommodate a new power plant of similar size or a new high voltage transmission line with similar capacity.

• Any new voltage problems can be corrected by new reactive control devices, such as capacitors or SVCs.

• Flow changes caused by cable failure would be rapidly corrected by power transfer to the unfaulted cable.

• Conclusion: From a power flow perspective the integration of the SCDC system is straightforward.

Transient Stability Analysis

• Transient stability analysis, the study of whether all the system generators will retain synchronism following a system disturbance, is a critical question.

• The assumed fault scenario was to apply a balanced, three phase, solid fault at each of the five SCDC cable terminals. The fault was then cleared after three cycles (0.05 seconds). Different scenarios were then considered for the pick in the SCDC injections:– None (both cables failed)– Half (no transfer of power from the faulted cable)– Half, then ramp to full over either 1 second or 5 seconds

Frequencies for All Generators; Complete Loss of Both Cables

Values are generator frequencies in HzMinimum Frequency is about 59.58 Hz

Frequencies for Selected Generators; Complete Loss of Both Cables

Example of Governor Response for Loss of 10 GW

Gen 1GASTON5 #5 Mech Input


Time in Seconds1514131211109876543210

Gen

1G

ASTO

N5

#5 M

ech

Inpu

t

860

859

858

857

856

855

854

853

852

851

850

849

848

847

846

845

844

Given a loss of 10 GW for a 676 GW system,a proportionalgeneration increasefor this generatorwould be 0.844/676*10 GW= 12.4 MW. Actual is slightly different becauseof differing gover-nor characteristics

Frequencies for All Generators; Loss of One Cable; No MW Transfer

Minimum Frequency is about 59.70 Hz

Frequencies for Selected Generators; Loss of One Cable; No MW Transfer

Frequencies for All Generators; Loss of One Cable; 5 Sec MW Ramp


Frequencies for Selected Generators; Loss of One Cable; 5 Sec MW Ramp

Example of Governor Response for 5 Second Ramp Recovery



Time in Seconds1514131211109876543210

Gen

1G

ASTO

N5

#5 M

ech

Inpu

t

849

848

847

846

845

844

In previous plot forthis governor (for thecomplete loss ofboth cables case)the output went up to860 MW. Now inrecovers quite quickly to its pre-contingency value

Frequencies for All Generators; Loss of One Cable; 1 Sec MW Ramp


Frequencies for Selected Generators; Loss of One Cable; 1 Sec MW Ramp

Frequency Response Discussion

• With no (or slow) power recovery the maximum frequency drop was about 0.3 Hz (done to 59.7) when only one cable failed (5 GW loss)– Well above highest load shed frequency of 59.3 Hz.

• Likely drop could be more because– Study considered peak summer load condition, which has

more generators spinning– Transient stability cases tend to under-estimate frequency

decline since not all governors are available

• But the modeled frequency decline tends to match actual results (see next slide)

April 23, 2002 Frequency Response Following Loss of 2600 MW

Decline for 2600MW was about 0.1 Hz, so 0.3 Hzfor 5000 MW is actually slightlyhigh. But chart atleft 1) only showsthe frequency at one location, notthe lowest frequencyand 2) measurementdelay may havemissed the lowestvalue.

Historical Eastern Interconnect Frequency Response

23

Source: “Interconnected Power System Response to Generation Governing: Present Practice andOutstanding Concerns,” IEEE Task Force on Large Interconnected Power System Response,IEEE Publication 07TP180, May 2007 (Figure 2-22)

Our valueswere about1700 MW/0.1Hz for the 5 GW loss case(one cable)and 2500 for the 10 GWLoss case(both cables)

Frequency Propagation Animation

• The accompanying slide set shows an animation of the frequency for the first four seconds for the 5 second ramp recovery case.

Eastern Interconnect Transient Stability Conclusions

• From a transient stability point of view, a 10 GW SCDC cable could be integrated into the existing Eastern Interconnect.

• Frequency response is fairly insensitive to how quickly the power is transferred from faulted cable to the unfaulted cable (one versus five seconds)– Transfer time does affect how much power needs to be picked

up by the generator governors, and for how long.

WECC System

• The system studied was the WECC 2010 LA1-SA Approved Base Case.

• Case has 15,795 buses, 3100 generators, a total load of 106 GW and total generation of 111 GW.

• 2006 series dynamic models.• Power flow and transient stability runs were done

using PowerWorld Simulator version 14.• Case had several minor initial flow violations.

Power flow and contingency limits were not considered

26

WECC SCDC Cable Route: Six Stations, 8.5 GW

27

8500 MW Asynchronous Generation

Denver: 1500.0 MW

Alburquerque: 1000.0 MW

Phoenix2000.0 MW

SanDiego: 1500.0 MW

Los Angles: 2500.0 MW

Freq. Deviation for All Generators; Loss of One Cable: Worst Case

28

Freq. Deviation for All Generators; Loss of One Cable; 8 Sec MW Ramp

29


30


31


32

Comparison with ActualWECC Frequency Results

33

Source: L. Pereira, et. al., “New Thermal Governor Model Selection and Validation in the WECC,” IEEE Transactions on Power Systems, February 2004, pp. 517-523 (Figure 1).

WECC FrequencyResponses Tendsto be Around800 or 900 MW/0.1 Hz. So a 4.25 GWsustained loss would result in an anticipated frequency declineof close about 0.5 Hz, slightly above the 59.3 load shed threshold.

WECC Transient Stability Conclusions

• From a transient stability point of view, an 8.5 GW SCDC cable could be integrated into the existing WECC Interconnect provided following a fault the power can be quickly transferred to the unfaulted cable.

• Quick power transfer (several seconds maximum) can reduce the point of maximum frequency dip, which occurs at about five seconds in both the simulations and with actual system results.

34

1

Slides Show Locational Variation in Bus Frequency for the 5 Second Ramp Eastern Case

This presentation is based on work is being performed under contract with EPRI

Tom OverbyeUniversity of Illinois and PowerWorld Corporation

Eighth EPRI Superconductivity ConferenceNovember 12-13, 2008

Transient Stability Frequency Animation: Time = 0.0 Seconds

Time: 0.1 Seconds

Time: 0.2 Seconds

Time: 0.3 Seconds

Time: 0.4 Seconds

Time: 0.5 Seconds

Time: 0.6 Seconds

Time: 0.7 Seconds

Time: 0.8 Seconds

Time: 0.9 Seconds

Time: 1.0 Seconds

Time: 1.1 Seconds

Time: 1.2 Seconds

Time: 1.3 Seconds

Time: 1.4 Seconds

Time: 1.5 Seconds

Time: 1.6 Seconds

Time: 1.7 Seconds

Time: 1.8 Seconds

Time: 1.9 Seconds

Time: 2.0 Seconds

Time: 2.1 Seconds

Time: 2.2 Seconds

Time: 2.3 Seconds

Time: 2.4 Seconds

Time: 2.5 Seconds

Time: 2.6 Seconds

Time: 2.7 Seconds

Time: 2.8 Seconds

Time: 2.9 Seconds

Time: 3.0 Seconds

Time: 3.1 Seconds

Time: 3.2 Seconds

Time: 3.3 Seconds

Time: 3.4 Seconds

Time: 3.5 Seconds

Time: 3.6 Seconds

Time: 3.7 Seconds

Time: 3.8 Seconds

Time: 3.9 Seconds

Time: 4.0 Seconds

November 12 & 13, 2008

Eighth EPRI Superconductivity Conference

Issues Associated with a Superconducting DC Line

Fed by a Multi‐Terminal VSC System

Tom Baldwin, Florida State Univ.Paulo Ribeiro, Calvin College, and Brian Johnson, Univ. of Idaho

November 12 & 13, 2008 Eighth EPRI Superconductivity Conference 2

Outline

• Enabling Technologies:– High Power Voltage Source Converters– DC Superconducting Cables

• Topologies– Multi‐Tap VSCs Issues

• DC Power Control– Rectifiers / Inverters– Dealing with Transient Current/Power Variations– Practical Power and Current Limitations

• Discussions


SCDC Control Analysis and Simulations

• Cable model from– W. Hassenzahl, “A high‐power superconducting dc cable, an EPRI program”

SCDC Project Review Meeting, Charlotte, NC, 10 December 2007

• System model from– S. Nilsson and A. Daneshpooy, “Simulation of HTSC HVDC system,”

SCDC Project Review Meeting, Palo Alto, CA, 25 July 2008

SCDC cable electrical characteristicsParameter Valueouter radius of inner conductor 17.5 mminner radius of outer conductor 29.5 mmCalculated Quantities Valueinductance, L 104.4 nH/mcapacitance, C 319.6 pF/mcharacteristic impedance, Z0 18.08 Ωpropagation speed, ν 173 x 106 m/s

System Parameter ValueSCDC cable length, l 2000 milescable propagation delay, tDelay 18.6 msControl Variables Valuemaximum voltage ramp rate 40 kV/s


Transient Oscillations of DC Cables

• Long DC cable system (>1000 km)– the behavior of the converters are affected by the propagation delays introduced by the cables

• the propagation time constant is similar to other cable systems

• with a small frequency‐dependent ac resistance provided by SCDC cables, slower transient signals (<1 kHz) have little attenuated along the cable length

• normal mismatches between the converter impedance and the cable characteristic impedance cause most of the transient signal energy to reflect back into the cable


Rectifier Terminal-Voltage Control

Inverter Terminal-Current Control Rectifier Terminal-Current Injection Inverter Terminal-Current Injection

Rectifier Terminal-Voltage Level Inverter Terminal-Voltage Level

current ramping to full load at the rate of 5 kA per second

voltage control at the rectifier maintains the dc terminal

voltage at nearly constant valuefor load current changes

voltage level at the inverterterminal exhibits a voltage sag during the ramping up of the

load current

voltage ramping to pre‐chargethe voltage in the SCDC cable

ringing of the current feeding the cable complementary

ringing of the current at the inverter

terminal of the cable


Ramp Rate Limits for Long Cables• A proper voltage profile is

maintained at the converter with voltage control

• The voltage at a converter with current control sags and swells due to the inductance of the SCDC cable

• The propagation delay and mismatch of the cable’s characteristic impedance with the converter’s impedance results in a decaying oscillation

• The ramp rate of the current affect the magnitudes of the voltage sags, swells, and ringing

Case Peak Idc Greatest Vdc Average VdcRamp Rate Sag Sag

Run #1 1 kA/s -0.38% (79.7 kV) -0.19% (79.85 kV)Run #2 2 kA/s -0.88% (79.3 kV) -0.44% (79.65 kV)Run #3 5 kA/s -2.75% (77.8 kV) -1.38% (78.90 kV)Run #4 10 kA/s -5.50% (75.6 kV) -2.75% (77.80 kV)Run #5 20 kA/s -11.0% (71.2 kV) -5.50% (75.60 kV)

Sags for the 2000-mile SCDC cable


Impact of Cable Length1000‐mile cable

2000‐mile cable 4000‐mile cable

• Simulation parameters• 80 kV, 10 kA, two‐terminal SCDC cable

• current control terminal: 2 kA / sec ramp rate

• Graphs of voltage ripple

1.13% V_offset2.22% V_ripple




VSC Model

Single DC pole operationand a SCDC cable with ground return sheath


1000 km Typical DC Cable

Transient Oscillations


1000 km Small Resistance DC Cable



1000 km Near Superconducting DC Cable



1000 km Near Superconducting DC Cable


Curren

t [kA

]


Comments

• PSCAD simulations show– that the operation of the VSC converters seem to work adequately as far as the control of voltage is concerned

– however the current transients on the DC line for near superconducting conditions after an AC fault are extremely severe and needs to be dealt with creative solutions and may not be easily achieved


Control Schemes

• Multi‐terminal systems– extensions of the point‐to‐point system control concepts (based on the notion of control modes)

• voltage regulation mode at one converter station– generally applied to a rectifying converter

• current regulation mode at all other converter stations


DC Voltage Droop Control

• A distributed voltage regulation scheme for controlling current injections– similar to frequency‐power regulation in ac grids

• a change in voltage used to signal the control system to meet changes in power demand (current injections)

• natural regulation requiring no communications

– performs best on a SCDC mesh or parallel network• each of the nodes reach the same steady‐state voltage level


Dynamics of Droop Control

• The droop dynamic components– VSC rectifier’s equivalent source impedance– DC capacitors at the terminals of each converter– SCDC cable inductance– SCDC propagation delay for long lines (>1000 km)

• Droop dynamic range– the built‐in droop of a rectifying converter is quite small (e.g., 10’s MW / 0.001 pu of ΔV)

• simplifies the power regulation at inverting converters• large changes in the dc voltage can indicate system problems and trigger load shedding as necessary


Dynamics with Long SCDC Cables

• Two of the long cable dynamic characteristics cause a voltage differential across the SCDC cable– inductance– propagation delay

• Control scheme must account for the propagation delay of the cable– delay values: 1 ms to 25 ms


Two Cable System

• Proposed from a reliability perspective– twin converters and twin cables running in parallel– crossover switches for addressing faulted sections

• From a control perspective:– using both cables simultaneously permits a doubling of the current ramp rates for a specified sag, swell, and ripple requirement

– in the case of a failure, half of the full rated current would need be transferred to the remaining good cable or converter

Copyright © 2008, Praxair Technology, Inc. All rights reserved.8th Annual EPRI Superconductivity Conference

Pulse Tube Cryocooler Refrigeration System for HTS Cables

Praxair, Inc. Greg Henzler

November 13, 2008

28th Annual EPRI Superconductivity Conference Copyright © 2008, Praxair Technology, Inc. All rights reserved.

Outline

Praxair introduction

Pulse tube cryocooler technology

Columbus, OH cryocooler experience

HTS refrigeration system layout


Praxair at a Glance

A Fortune 300 company

Sales of $9.4 billion in 2007

Largest industrial gas company in North America

Operations in more than 30 countries

One million customers worldwide

28,000 employees


NorthAmerica

55%

SouthAmerica

17%

Europe14%

Asia8%

Industrial Gases Sales by Region2007 Sales $9.4 billion

Excludes worldwide sales of Praxair Surface Technologies (6% of total sales)

Strategic Global Position


On-Site Supply Business Model

Plants are located on customer sitesAir separation, H2 and other types of plants

Owned, operated, maintained and updated by PraxairRemote operation and monitoringReliably supply product 24/7 Critical customers include

Hospitals

Chemical plants

Semiconductor fabs

Steel mills

Praxair is viewed as a gas utility by many of our customers


Praxair’s Pulse Tube Cryocoolers

Pressure wave generator (PWG) converts electrical energy into acoustical energy

Coldhead and inertance network convert acoustical energy into refrigeration capability

Process Lines

PWG

Vacuum Container

Coldhead

Coldhead InertanceNetwork

Inertance Tank

Linear Motors with Pistons


Pulse Tube Benefits

No moving parts in cold endNo connecting rods

No wearing partsNo bearings

No oil

Long lifeHigh reliabilityLow maintenanceHigh Carnot efficiencySmall modular footprintLow noise and vibrationEnvironmentally friendly

Key enabler of HTS cable technology!


Linear Motor

Regenerator Pulse Tube

Aftercooler

Reservoir

ImpedanceNetwork

Cold Heat Exchanger

Warm Heat Exchanger

Major components of electrically driven Pulse-tube cryocoolersLinear motor: electrically powered oscillating piston(s)

Aftercooler: water cooled heat exchanger

Regenerator: array of narrow passages - high Cp material

Cold heat exchanger: refrigeration is ‘extracted’ here

Pulse tube

Warm heat exchanger, impedance network, reservoir, oscillating gas

Pulse Tube Basics


PWG & Cold Head Improvements

2nd generation PWGImproved efficiencyIncreased clearanceExternal thermal management systemNew drift control systemShorter piston stroke length

2nd generation cold headDesign completedHigher cooling capacityImproved heat transferEnhanced regenerator

40 60 80 100 1200

500

1000

1500

2000

2500

3000

Tc, K

Cooling Power, W

1K Unit and Gen-2

1kW

G2


Columbus, OH HTS Cable Project

HTS cable energized 8/8/06~ 20,000 hours of operation

2nd gen. PWG energized 8/20/08

~ 2,000 hours of operation at site

Praxair operates, maintains and monitors refrigeration system

System working well

Termination CryostatRefrigeration System

Chiller

1 kW Cryocooler

PT Cryocoolers


Termination Refrigeration System

85%87%89%91%93%95%97%98%Percent of design capacity per cryocooler =

Cryocooler Shutdown

At full refrigeration demand of5 kW, the cryocoolers operateat 85% of their full capacity.

A loss of 1 cryocooler at full refrigerationdemand results in the remaining cryocoolersoperating at 98% of their full capacity.


Refrigeration System for Long Lengths

Cryocoolers at the substations only

GORETURNGO

RETURN

cooling channels

cryostat

cable

steel pipe


Cooling System Key Components

Pressure Wave Generator (PWG)Two opposing pistons on linear motors

ColdheadHeat exchangers and regeneratorNo moving parts

Water chillerPackaged unit

Cold boxCryo valves, piping, pumps etc.

ControlsVFDTemperature, pressure, vibration etc.

Majority of components are existing technology and readily available.


Benefits of Independent Cryocoolers

Each cryocooler is operated by a single PWGIf a motor fails, then only one cryocooler failsEach cryocooler acts independentlyLeads to overall higher reliabilityManage redundancy on a smaller scaleMore turndown flexibility


Conclusions

Praxair reliably supplies product for critical applications in diverse industries

Pulse tube cryocoolers are a key enabler for HTS cable applications

Praxair continues to have significant success with pulse tube cryocooler technology

1 Managed by UT-Battellefor the Department of Energy

Bill SchwenterlyOak Ridge National Laboratory

Ed PlevaWaukesha Electric Systems

Alan WolskyArgonne National Laboratory

November 13, 20088th EPRI Superconductivity

Conference

Cost and Performance Comparisons Between HTS And Conventional Utility Power

Transformers


OUTLINEDesign assumptions

Overview of design spreadsheet

Capital and Operating Cost Comparison

Efficiency Comparison

Weight and Dimension Comparison

Other Design Issues

Summary of Requirements


HTS Unit Design Summary25-MVA rating; 115 kV / 13.09 kV; 72 A / 1103 AYBCO winding in pressurized, subcooled nitrogen bath

HV– Disc, 10 turns/discLV– Transposed screw, 8 wide or 16 narrow tapes in parallelWrapped insulation on conductorsCo-wound 1-mm copper

Pressurized bath is coupled to cryocooler by cooling shell.

Air-cooled compressorsComposite dewar

Metal dewar would form a shorted turn around core.Core in air


Conventional vs. HTS Unit Ratings Comparison

Conventional Unit15/20/25-MVA ratings with no fans/1-stage fans/2-stages fans.30 minute operation at 50 MVA with increasing winding temperature.

HTS UnitCryocoolers are sized for 25-MVA heat load.HTS is sized for 50-MVA load with Ipeak < Ic.15/20/25-MVA ratings with cryocoolers cycled to match heat loads at lower ratings.30 minute operation at 50 MVA with liquid nitrogen boiloff.Current leads are sized for 125% of 25-MVA current.Maximum current lead temperature rises to 120°C at 50 MVA with increased heat load.


Transformer SchematicBushings

Cryocooler

Shield

CoreWinding Foam

Composite CoilDewar

CoolingShell

PressurizedSubcooledNitrogen

RemovableTop Plate

Unit is surrounded by weather enclosure in place of oil tank.


Single-Phase Transformer Concept

Core

Composite Dewar

AL-300 Cryocooler

138-kV Bushing

Winding PackCooling Shell


Common Dewar for 3-Phase Unit

Stainless outer jacket

Composite top & bottom plates

Composite core limb jackets and winding vessels


Overview of HTS Unit Design Spreadsheet

Inputs:Ratings and voltages; overload factor5 different volt/turn values can be specifiedConductor dimensionsWinding geometry– disc or layer; number of layers or disc turnsMaterials properties– Ic, cost, densityWall thickness for coil structure and dewarsInsulation thickness and voltage standoff distancesRefrigerator dimensions, weight, input power, cost

Outputs:Capital and operating costsWinding, dewar, core, and enclosure dimensionsWeights-conductor, core, dewarLength of conductorLead and ac loss heat loads (Rhyner’s equations for ac losses)Room temperature input loss power% Fault impedance


15-MVA 30-Year Capital and Operating Costs

Assumptions: $50/kA-m HTS, 350 A/cm, 0.6 cm width, 70-K Toper$8.80/kg copper, $4.20/kg steel 120 V/turnLoad losses– $1250/kW No-load losses– $2500/kW

Item HTS Conventional

Selling Price $680 K $458K

No-Load Loss $84 K, 34 kW $35 K, 14 kW

Load Loss $4K, 3.3 kW $58K, 46 kW

TOTAL $768 K $551 K

Oil Containment ---- $30 K

Fire Suppression ---- $100 K

Refr. Maintenance (2 AL-600) $106 K ----

GRAND TOTAL $874 K $681 K


High cost of conductor forces minimum in lifetime cost to high volt/turn values.

V/n gives required number of turns in a phase.

V/n = απRcore2

α = 4.44 f Bcore

Lcond = 2πRcoren = 2V/αRcore

Thus, larger core diameter reduces conductor length.


15- and 25-MVA EfficiencyAssumptions: Refrigerator COP– 27 W/W.

2 Cryomech AL-600 refrigerators, ea. 560 W at 70 K, 15 kW input power.HTS and Lead losses are refrigerator input power.


Load 15 MVA 25 MVA 15 MVA 25 MVA

Core Loss 23 kW 14 kW

AC Loss 2.9 kW 13.1 kW ----

Lead Loss 7.4 kW 8.8 kW ----

Copper Loss ---- 46 kW 131 kW

TOTAL LOSS 33.3 kW 44.9 kW 60 kW 145 kW

EFFICIENCY 99.8 % 99.8 % 99.6 % 99.4 %


15-MVA Dimensions and WeightsAssumptions: 0.3 m side and 0.1 m top/bottom enclosure clearances


Length 3.75 m including compressors 3.02 m

Width 1.65 m 3.33 m including radiators

Height 4.22 m including bushings 4.92 m including bushings

Core weight 16.4 t 9.1 t

Total weight 24.0 t 39.9 t


What if conductor cost is lowered?Minimum in total cost moves down and to left as conductor cost falls.

Capital cost approaches conventional at $10/kA-m.

Copper– ~$25/kA/m in conventional unit at 3A/mm2.Capital costs shown are atminimum total lifetime cost.

Refrigerator cost reduction ($109K in present design) would also help cost comparison.


15-MVA 30-Year Capital and Operating Costs

Assumptions: $20/kA-m HTS, 350 A/cm, 0.6 cm width, 70-K Toper$8.80/kg copper, $4.20/kg steel 70 V/turnLoad losses– $1250/kW No-load losses– $2500/kWRefrigerator cost reduced by half


Selling Price $478 K $458K

No-Load Loss $60 K, 24 kW $35 K, 14 kW

Load Loss $5K, 4 kW $58K, 46 kW

TOTAL $543 K $551 K

Oil Containment ---- $30 K

Fire Suppression ---- $100 K

Refr. Maintenance (2 AL-600) $106 K ----

GRAND TOTAL $649 K $681 K


Other Design Issues– Fault HandlingIEEE/ANSI Standards specify a 2-sec total fault duration without overheating.Extra copper is needed for fault handling.

2-sec requirement leads to large fraction of a conventional unit’s Cu!1 mm of copper is adequate for 1/2-sec 10X fault.

Copper cannot be co-insulated with HTS tapein advance because the inner conductorbuckles during winding.

HTS tape is too fragile to wind with high-voltageinsulation by itself.Winding on insulation as coil is wound is not practical,especially for multiple conductors in LV winding.

Need copper laminated or plated on both sides of the HTS tape,so that the HTS is on the neutral axis.This would provide a robust conductor that could be insulated ona high-speed machine.

HTS

Copper

Insulation


Other Design Issues– Layer Build, Core,AC Losses

Designs with ~20-turn discs are desirable.Core limbs >2 m high are flexible and hard to handle in shop.Smaller core with shorter limbs and lower losses is possible with more turns in discs.At constant window area,h/w ratio of β = 4/3 minimizes core loss.

Window area Aw = hw = βw2 = h2/βCore volume Vcore = Acore[3h + 2(2w+3Dcore)]Vcore = Acore[3√ Awβ + 4 √ Aw/β + 6Dcore]Derivative = 0 with β = 4/3.

BUT-- more turns on a disc raises field on HTS conductor on inner turns and increases ac loss.

HTS loss reduction needed– striations, nano-particles, etc.

w

h


SUMMARY– For a competitive HTS Transformer:

We need HTS tape cost near $20/kA-m. *(Not including extra Cu)

We need HTS tape with 1/2 mm or more of copper laminated or plated on each side.

We need HTS tape with ac loss reduction features such as striations or nanoparticles.

We need reduced cryogenic refrigeration costs.

With higher no-load losses and lower load losses than a conventional unit, an HTS transformer is most appropriate in a base load application where it is loaded most of the time.

1018498_combined

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