technology, benefits, applications modern modern ... · pdf file3 july 2010 e t ps sl1 / en12...

Technology, Benefits, ApplicationsTechnology, Benefits, ApplicationsTechnology, Benefits, Applicationsmodern modern modern convertersconvertersconvertersvoltagevoltagevoltage sourcedsourcedsourced (VSC)(VSC)(VSC)modular modular modular multilevelmultilevelmultilevel (MMC)(MMC)(MMC)

ISIE 2010Power Transmission Solutions

July 2010

HVDC PLUSThe smart way - One Step ahead

Energy Sector© Siemens AG 2010

2 July 2010 Energy SectorE T PS SL1 / EN12

Subjects of Presentation

HVDC Converter Basics

Windfarm Interconnector Solutions

HVDC PLUS – VSC MMC Application

HVDC PLUS – VSC MMC Design Details

Multiterminal HVDC (MTDC)


HVDC Converter Technologies

Semiconductor switches with turn-on and turn-off capability, e.g. IGBTs

Thyristors with turn-on capability only

Self-commutated Voltage-sourced converter (VSC)

Line-commutated current-sourced converter (LCC)

HVDC PLUSHVDC Classic

Changing technologies drive changing solutions


General Features of VSC Technology

Grid access for weak AC networks (e.g. platforms)

Good dynamic performance

Independent control of active and reactive power

Supply of passive networks (Black-Start Capability)

Low space requirements

HVDC PLUS offers such additional benefits


-1.00

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

1.00

-1.25 -1.00 -0.75 -0.50 -0.25 0.00 0.25 0.50 0.75 1.00 1.25

P [p.u.]

Q [p

.u.]

HVDC PLUS (VSC - MMC)typical P/Q diagram

Rectifier Inverter

“over-excited”

“under-excited”

The reactive power can be controlled to any value within the limiting characteristics

Current Limit

Voltage Limit

Design Specification


VSC Technology – A look backTwo level converter

+Ud/2

-Ud/2

High level of harmonic distortionHigh steep front voltages resulting in HF noise and stress of component insulation

Desired voltageRealized voltage

α−

α−

α−

α−

α−

α−

α−

α− α− α− α− α−


Modular Multilevel Converter - MMC

Low level of harmonics and HF noise

Low switching losses

Modular arrangement with identical two-terminal power modules

Ud

Uac

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+

+Ud/2

-Ud/2


HVDC PLUS with MMC – Basic Scheme

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

ud

Phase Unit

Vd

IGBT2D2

D1IGBT1

Power Module (PM)

PowerElectronics

Converter Arm


Phase Unit

HVDC PLUS with MMC

Modular Multilevel Converter

PLUSCONTROL

Power Module


States of Power Modules

Energization Capacitor On Capacitor Off(converter blocked)

(charging) (charging)

(discharging)


MMC – perfect Voltage Generation

VConv.

- Vd /2

0

+Vd /2

AC and DC Voltages controlled by Converter Module Voltages:

VAC


Id

-Ud/2

+Ud/2

ControlIac /2

Iac /2Id /3

Iac

MMC – AC & DC Converter Currents ...

… controlled by Voltage Sources


=

~

=

=

~

=

=

~

=

n

2

1

1

2

n

Converter Reactors

Phase Unit

Parallel connection of three voltage sources

Damp balancing currents between different phases

Limit current gradient during severe faults


=

~

=

=

~

=

=

~

=

n

2

1

1

2

n

Power Electronics Module - Redundancy

Phase Unit

PLUSCONTROL

Power Module

High-Speed Bypass Switch

Single Module Failure


Complete ConverterLine-to-Line DC Fault

ikM

+

+

+

+

+

+

+

+

+

+

+

+

AC Grid

L1P L2P L3P

L1N L2N L3N

ik

ik


=

~

=

=

~

=

=

~

=

n

2

1

1

2

n

Line-to-Line DC Fault

PLUSCONTROL

Power Module

Protective Thyristor Switch

Phase Unit


Power Module

Control:- IGBTs- Bypass Switch- Bypass Thyristor

Monitoring:- IGBT on-state voltage- Capacitor Voltage- Loss of Capacitance

All signal exchange between the Power Module and the Module Management System is via two optical fibers


PLUSCONTROL Main Tasks – Current Control & Module Management

Individual switching of Power Modules

Power Module Charge Balancing

1

2

n

SIMATIC TDCC&P System

Measuring System

Calculation of required Converter Arm voltages

Control of active and reactive power

Current & Voltage Balancing Control

Power Module Monitoring


Control and ProtectionSystem Hierarchy Win-TDC with PLUSCONTROL

PLUSCONTROL

MMS nMMS 1

SCADA Interface

C&P Level

Operator Level

Switchgear & Auxiliaries Voltages & Currents Converter – Power Modules

SCADA Interface

RCIRCI

I/O Unit I/O Unit

I/O Level Measuring System

Remote HMI Local HMI

CCS

SIMATIC TDC

Win-TDC

SIMATICWinCC

Current Control System

Module Management System


HVDC PLUS with MMC – Basic Scheme

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

PM 1

PM 2

PM n

ud

Phase Unit

Vd

IGBT2D2

D1IGBT1

Power Module (PM)

PowerElectronics

Converter Arm


Modular Design: Power Module

The Power Module- a two terminal component

Capacitor Unit

Power ElectronicsPower ElectronicsPower Electronics

series connected Power Modules


HVDC PLUS (VSC – MMC)converter tower arrangements


Parallel Water Cooling

It provides all IGBTs in the power modules with the same cooling water temperature Electrolytic currents are minimized by the use of grading electrodesCareful choice of materials allows operation without de-oxygenizing equipment None of these systems had corrosion problems

a Power Module / b Heat Sink / c Piping / d Manifold

The Siemens Design of the Valve-Cooling Circuit with Parallel-Water Coolinghas been in Operation for more than 30 Years with thyristors


HVDC PLUSdecreasing Converter Station Losses

HVDC PLUS Station Losses at Nominal Load

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

2006 2007 2008 2009 2010

R & D and System Engineering Progress

Loss

esin

%

30 M

W T

est F

acili

ty

Tran

s B

ay C

able

- Ambient Conditions & Cooling Concept

- Power Rating & Operation Specification

- Transformer & Aux. Power Concept


HVDC PLUSVSC - MMC topology - features and benefits

Low semiconductor switching frequency

Low generation of harmonics

High modularity in hardware and softwareUse of well-proven standard componentsSinus shaped AC voltage waveforms

Easy scalability

Reduced number of primary components

Low converter losses

No filters required

High flexibility, economical from low to high power ratings High availability of state-of-the-art components Use of standard AC transformers

Low engineering efforts

High reliability,low maintenance requirements


HVDC PLUS Monopolar Configuration – Overview

tertiary winding(optional)

conventional AC transformers

secondary breaker(optional)

star point reactor 2nd star point reactor(optional)

secondary breaker(optional)


HVDC PLUSincreasing in maximum power range


HVDC PLUS ApplicationLarge Interconnectors

Link 11000 MW

Link 21000 MW

Converter Stationsin a land cable system


Supply of HVDC PLUS converter transformer

31

Logistic challengeHeavy duty transports

Transformer tank of severalhundred tons= largest indivisible item

Transformer oil(non hazardous goods)

several hundred tons have to be on site at the same time, supplied in container tanks and small quantity in barrels

General cargo

Accessories have to be on siteat same time

EXAMPLE


photographs show challenging dimensions

HVDC PLUS in applicationChallenging Transformer Transports

Coordination isnecessary to designtransformer dimensionsmatching to clearancesof obstacles on roadtransport routes and suitable transportequipment

Railwaybridgeacrossroad


HVDC PLUS in applicationTransformer Transport Solution

Correlation of design solution with transport equipment

low clearance below the viaduct require transport of tansformer tank in a bridge of long side girders carried on two multi-axle trailers (as below)Route survey of transport specialists has to confirm their transport equip-ment is suitable and all maneuvers to pass the obstacle are possible


HVDC PLUS for Grid AccessOffshore Windfarm project solutions

HVDC Link

OffshoreAC-System

OnshoreAC-Grid


HVDC PLUS ApplicationsConnection of remote Offshore Windfarms

Offshore Steady State Requirements- Blackstart and Power Reversal- Voltage and Frequency Control by Converter- Active Power determined by wind speed- Reactive Power control by Wind Farm within limits

Onshore & Offshore Faults- Reactive current injection from HVDC

AC Voltage Restoration / AC Protection

Onshore Faults- Concept for Fault-Ride-Through of Windfarm:

(i) Fast Telecom (ms) Windfarm Main Controller

(ii) Offshore Frequency Increase Overfrequency Detection in (ms)

(iii) “Mirroring“of Onshore Fault LVRT of Different Turbine TypesSC Current Contribution

(iv) Onshore Chopper Complete Isolation of Onshore Faults


HVDC PLUS ApplicationDC Transmission System with Onshore Chopper

Offshore Onshore

Multilevel Chopper Module

PM Electronics

+


HVDC PLUS and WIPOS: BorWin 2, Germany – World’s first VSC HVDC with 800 MW

38 E T PS SL/Re Power Transmission Division06-2010

2013

~ == ~ ==

~= =

~= =

Wind Farms: Veja Mate and Global Tech 1 – 800 MW,located 125 km Offshore (Northwest of the Island of Borkum)

The Siemens Wind Power Offshore Substation (WIPOS) is designed as a floating, self-lifting Platform

The Platform will be towed by Tugs to its Destination at Sea, where the Water is about 40 meters deep

A large heavy-duty Crane vessel is not needed to lift the Topside onto its Foundation

The Modular Multilevel VSCTechnology (MMC) reduces Complexity and therefore the Space required for Installation


Grid Access of Green Energy with HVDC PLUS:WIPOS – Advanced Offshore Platform Layout *

39 Power Transmission Division02-2010 E T PS SL/Re

Siemens Wind Power Offshore Substation (WIPOS) is designed as a floating, self-lifting *Platform

The Platform will be towed by Tugs to its Destination at Sea, where the Water is about 40 meters deep

A large heavy-duty Crane vessel is not needed to lift the Top-side onto its Foundation

The Modular Multilevel VSC Technology (MMC) reduces Complexity and therefore the Space required for Installation


HVDC PLUSContract for Borwin 2 Offshore HVDC

Overview OWP, Cable routes and Connection Points

Borwin 2Converter StationsPower 800MW @ +/-300kV DCone station on Offshore PlatformOffshore Wind Parks (OWP): Veja

Mate (Bard), Global Tech 1 (Wetfeet) each 400MW rated

DC-Cable 300 kV extruded:- 127 km Submarine Cable- 75 km Land CableAC-Cable 150kV: 39 km- OWP-ConnectionService Contract

Transpower Project

Diele / Börde

Büttel


HVDC PLUS for Grid AccessOffshore Windfarm project solutions

A

100 km

100 km

300 km

C

B

400 MW

400 MW

400 MW

C

200 MW

200 MW

200 MW

MTDC in full scale:4 x +/-300 kV

Combined DC/AC:2 x +/-300 kV& AC Compensation

Converter Rating:


HVDC PLUS with MultiterminalsMTDC: Udc control concepts

1. Master-Slave Stations- Power is determined by

all but one station- Master station controls Udc

Reliability of Master determinesOverall System Performance

Converter Station 2

M

M

~

=

=

Converter Station 3

M

M

~

=

=

M

Converter Station 1

M

M

~

=

=

M

2. Identical Udc/P Droop Stations- Udc/P droop is analogous to

Power-Frequency Control in AC systems

Voltage Disturbance causes Primary Reaction: Power infeed according to Udc/P Droop

Secondary Control restores load flow


HVDC PLUS with MultiterminalsMTDC with DC Faults

HVDC PLUS Converter Fault Pattern:

1. Low impedance DC faults / Udc decreases sharply: Power Module capacitors clamped via D1No transient discharge events

2. Uncontrolled charging currents from AC Side:Fault current amplitude >10kA exceeds IGBT current rangeThyristor prevents thermal overload of D2

Required Fault Clearing Time in 50…100 ms RangeEasy Recovery of HVDC PLUS

Selective Fault Clearing DC Grids:

Concepts for:DC resonance breakers (existing HVDC classic)Semiconductor breakers (R&D)

PM Electronics

+D1

D2


Thank You!

Schutzvermerk / Copyright-VermerkPower Transmission and Distribution

technology, benefits, applications modern modern ... · pdf file3 july 2010 e t ps sl1 / en12...

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