power electronics in a smart-grid distribution system - dchopkins
TRANSCRIPT
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Power Electronics in a Smart-GridPower Electronics in a Smart-Grid
Distribution SystemDistribution System
Prof. Douglas C Hopkins, Ph.D.Dir. Electronic Power and Energy Research Laboratory
www.DCHopkins.Com
Prof. Mohammed Safiuddin, Ph.D.Dir. Power Conversion and Controls Laboratory
State University of New York at Buffalo
332 Bonner Hall
Buffalo, New York 14260-1900
+01-716-645-3115
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
COPYRIGHT PERMISSION
Some material contained in this document may be covered by
one or more copyright restrictions and are noted to the
authors’ best abilities.
Those who have attended an IEEE Seminar presented by Dr.
Douglas C. Hopkins are granted sole use as an extension of
the presented seminar.
Others are granted permission for sole use for their personal
advancement, but cannot extend to included information
copyrighted by others.
Please respect intellectual property restrictions.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
OutlineOutline
Introduction
• Course Admin
• Credentials
• Course Objective
UB Degree and Courses
“Smart Grid” Topical Discussion
System Structure of Interest
Background - ‘Transmission
System’ and FACTS
Technical Review
• Concept development
• 3-ph, Symmetry, Harmonics
• Power Control
• Power Flow
The Power Distribution System -
Identifying Critical Issues
• Standards
• Operating limits
• Case Study
Power Electronics Opportunities
• Transformers
• SSPC/SSCB
• Advanced Power Switches
Case Studies
• AC v. DC
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Course ObjectiveCourse Objective
This seminar focuses on the environment power electronics needs
to develop within to provide the “smart” delivery of electric power
from the sub-transmission system to the end user’s meter.
Topics are introduced from an electronics processing / power
electronics v. power systems perspective.
Excerpt from university course taught to power utility engineers.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Masters of EngineeringMasters of Engineering curriculum for practicingcurriculum for practicing
electric utility engineerselectric utility engineers
Offered at the University at Buffalo
Synchronous live broadcast on a trimester schedule
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
UB UB MEngMEng* Degree Courses* Degree CoursesEAS 521 Y Principles of Engineering Management I C. Chang
Basic engineering management functions of planning, organizing, leading, and controlling, as
applied to project, team, knowledge, group/department and global settings, including
discussion of the strengths and weaknesses of engineers as managers, and the engineering
management challenges in the new economy. Emphasis is placed on the integration of
engineering technologies and management. Students are to understand/practice the basic
functions in engineering management, the roles and perspectives of engineering managers,
and selected skills required to become effective engineering managers in the new millennium.
Text: Notes
EE 582 Y Power Systems Engineering I. D. C. Hopkins
Review of fundamentals of three-phase power systems, power circuit analysis, characterization
and modeling of power system components, such as transformers and transmission lines, for
study of power flow and system operation with extension to advanced power system
components.
Text: Power Systems Analysis & Design; Glover & Sarma - Chapters 2-5 & 8
EE 587 Y Special Topics in Electrical Power Distribution M. Safiuddin
System planning and design, surge protection, system protection, system power factor, power
system pollution, and system interfaces.
Text: ANSI/IEEE Stnd. 141-1993 [The Red Book], IEEE Press
*Synchronous on-line distance learning, accredited for internationally delivery
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
UB UB MEngMEng* Degree Courses * Degree Courses ((concon’’dd))
EE 583 Z Power Systems Engineering II J. Zirnheld
Investigate transmission line characteristics of aerial and underground lines including
development of their symmetrical component sequence impedances, Steady-state
performance of systems including methods of network solutions.
Text: Power System Analysis & Design; Glover & Sarma - Chapters 6-13 (except 8)
EE 641Y Power System Protection-Theory & Applications Ilya Grinberg
Power Systems Relay Protection. Principles of relay techniques (classical and solid state), current
and potential transformers and their application in relaying technique, over-current, differential,
impedance, frequency, overvoltage and undervoltage relays, relay protection of overhead and
underground power lines, generators, transformers, motors, and buses.
Text: Protective Relaying Theory and Applications, edited by W.A. Elmore, Marcel Dekker, 2nd
Rev & Ex Edition, Sept 2003.
EE 540Y Static Power Conversion for Power Systems D. C. Hopkins
Principles of operation of static compensators and basic configurations; series, shunt and shunt-
series; flexible ac transmission systems (FACTS); line and self commutated controllers,
configurations and control aspects; applications to power distribution systems; performance
evaluation and practical applications of static compensators.
Text: Understanding FACTS- Concepts & Technology of Flexible AC Transm. Syst.; Hingorani
and Gugyi
*Synchronous on-line distance learning, accredited for internationally delivery
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
UB UB MEngMEng* Degree Courses * Degree Courses ((concon’’dd))
EE 598- Contemporary Issues in Electrical Power Industry- [Independent Study] M.
Safiuddin
Energy Management Issues - Supply/Demand/Conservation
Electrical Power System Quality and Reliability
Industry Restructuring - Pains & Gains- Who is really in charge?
Electrical Power Generation and Global Warming; Cost Effectiveness Issues
EE 606Y- Distributed Generation: M. Safiuddin
Historical perspective of electric power industry, fundamentals of distributed generation,
economics of distributed resources, Micro-turbines, fuel cells, solar and wind power systems.
Text: Renewable and Efficient Power Systems; Gilbert M. Masters; IEEE Press;
*Synchronous on-line distance learning, accredited for internationally delivery
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
““SMART GRIDSMART GRID”” - Topical Discussion - Topical Discussion
TOPICAL DISCUSSION WAS OMMITTED FROM BOOKLET
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http://www.aertc.org/conference09/index.html
The Advanced Energy 2010 conference includesprograms each morning, general sessionsfeaturing one or more keynote speakers, and aposter session. The educational program includesmultiple sessions involving topic experts andthought leaders on the following program tracks:
!Energy Policy, Energy Sector Finance!Battery/Energy Storage/Load Management!Intelligent Transmission, Distribution & Smart Grid!Solar, BioFuels, Wind, Geothermal, Tidal, Hydrogen
Economy!Low Carbon Society, Climate Change & Sustainable
Building!Intelligent Transportation!Energy Efficient Data Centers!Energy Efficient Lighting!Advanced Lighting
Research
Advanced Energy 2010 conferenceAdvanced Energy 2010 conference
"JimSmith" <[email protected]>,
2010
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
OUR CHALLENGEOUR CHALLENGE
- LEGACY DOMANANCE -- LEGACY DOMANANCE -
All Smart Grid initiatives will need to integrate with the
Legacy Systems.
Utilities have tremendous precedent that has been
maintained because of the“deep pockets” they offer
when good things might go wrong.
What is the primary “Legacy” hurdle?
STANDARDS
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Standards - A Critical ElementStandards - A Critical Element
NIST Special Publication 1108
NIST Framework and Roadmap for
Smart Grid Interoperability
Standards, Release 1.0
Office of the National Coordinator for Smart
Grid Interoperability
January 2010
www.nist.gov/public_affairs/releases/
smartgrid_interoperability_final.pdf
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
A breakdown of what to follow in theA breakdown of what to follow in the
NIST Standards ActivitiesNIST Standards Activities
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Deployment of various Smart Grid elements, including smart sensors on
distribution lines, smart meters in homes, and widely dispersed sources
of renewable energy, is already underway and will be accelerated as a
result of DOE Smart Grid Investment Grants etc.
Without standards, there is the potential for technologies developed or
implemented with sizable public and private investments to become
obsolete prematurely or to be implemented without measures
necessary to ensure security.
Why NIST FrameworkWhy NIST Framework
Under the Energy Independence and Security Act of 2007 (EISA), NIST
is assigned the
“primary responsibility to coordinate development of a framework that
includes protocols and model standards for information management to
achieve interoperability of Smart Grid devices and systems…”
There is an urgent need to establish protocols and standards for the
Smart Grid.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
• It describes a high-level conceptual reference model for the Smart Grid,
• identifies 75 existing standards that are applicable (or likely to beapplicable) to the ongoing development of the Smart Grid,
• specifies 15 high-priority gaps and harmonization issues (in addition tocyber security) for which new or revised standards and requirements areneeded,
• documents action plans with aggressive timelines by which designatedstandards-setting organizations (SSOs) will address these gaps,
• and describes the strategy to establish requirements and standards to helpensure Smart Grid cyber security
Why NIST Framework (Why NIST Framework (concon’’dd))Recognizing the urgency, NIST developed a
• three-phase plan to accelerate the identification of an initial set ofstandards and
• to establish a robust framework for the sustaining development of themany additional standards that will be needed and
• for setting up a conformity testing and certification infrastructure.
This document: NIST Framework and Roadmap for Smart GridInteroperability Standards, Release 1.0, is the output of the first phaseof the NIST plan.
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Lost inLost in WHAT IS THE SMART GRID?WHAT IS THE SMART GRID?
1.4 Content Overview - Areas worth reading1.4 Content Overview - Areas worth reading
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Primary PlayersPrimary Players
The market place will
be a primary driver
and should not be
overlooked
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Smart Grid Information NetworksSmart Grid Information Networks
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1.4 Content Overview1.4 Content Overview (Areas worth reading) (Areas worth reading)
Chapter 2, “Smart Grid Vision”
Chapter 3, “Conceptual Reference Model”
• presents a set of views (diagrams) and descriptions that are the basis for
discussing the characteristics, uses, behavior, interfaces, requirements, and
standards of the Smart Grid.
Chapter 4, “Standards Identified for Implementation”
• presents and describes existing standards and emerging specifications
applicable to the Smart Grid. It includes descriptions of proposed selection
criteria, a general overview of the standards identified by stakeholders in the
NIST- coordinated process, and a discussion of their relevance to Smart Grid
interoperability requirements.
Chapter 5 describes sixteen "Priority Action Plans”
Chapter 6, “Cyber Security Risk Management Framework and Strategy”
Chapter 7, “Next Steps”
Excellent orientation to
the Smart Grid Thrust
A “must follow”
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
What is important about the NIST REPORT andWhat is important about the NIST REPORT and
what is important for us to follow?what is important for us to follow?1.3.2 Applications and Requirements1.3.2 Applications and Requirements
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
[23] Federal Energy Regulatory Commission, Smart Grid Policy, 128 FERC ¶ 61,060 [Docket No. PL09-4-000] July 16, 2009.
1.3.2 Applications and Requirements1.3.2 Applications and Requirements
1.3.2 Applications and Requirements: Eight Priority Areas
To prioritize its work, NIST chose to focus on six key functionalities plus
cyber security and network communications,
• i.e. aspects that are especially critical to ongoing and near- term
deployments of Smart Grid technologies and services, including priority
applications were recommended by FERC in its policy statement:23
These “Areas” are: … [by color of importance to power electronics
opportunities]
Peripheral interest with traditional support from existing products
Direct interest as technology can advance in integrated functionality
Primary interest by advanced power electronic systems
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
1.3.21.3.2 Apps & Apps & ReqReq’’d d Priority AreasPriority Areas
Peripheral interest with traditional support from existing products
Wide-area situational awareness:
Demand response and consumer energy efficiency:
Cyber security:
Network communications:
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
1.3.21.3.2 Apps & Apps & ReqReq’’d d Priority AreasPriority Areas ( (concon’’dd))
Direct interest as technology can advance in integrated functionality
Advanced metering infrastructure (AMI):
• Currently, utilities are focusing on developing AMI to implement residential
demand response and to serve as the chief mechanism for implementing
dynamic pricing.
• It consists of the communications hardware and software, and associated
system and data management software that creates a two-way network
between advanced meters and utility business systems, enabling
collection and distribution of information to customers and other parties,
such as the competitive retail supplier or the utility itself.
• AMI provides customers real-time (or near real-time) pricing of electricity,
and it can help utilities achieve necessary load reductions.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
1.3.21.3.2 Apps & Apps & ReqReq’’d d Priority AreasPriority Areas ( (concon’’dd))
Primary interest by advanced power electronic systems
Energy storage:
• Means of storing energy, directly or indirectly.
• The significant bulk energy storage technology available today is pumped
hydroelectric storage. New storage capabilities, especially for distributed
storage, would benefit the entire grid, from generation to end use.
Electric transportation:
• Refers, primarily, to enabling large-scale integration of plug-in electric
vehicles (PEVs).
• Electric transportation could significantly reduce U.S. dependence on
foreign oil, increase use of renewable sources of energy, and dramatically
reduce the nationユs carbon footprint.
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1.3.21.3.2 Apps & Apps & ReqReq’’d d Priority AreasPriority Areas ( (concon’’dd))
Distribution grid management:
• Focuses on maximizing performance of feeders, transformers, and other
components of networked distribution systems and integrating with
transmission systems and customer operations.
• As Smart Grid capabilities, such as AMI and demand response, are
developed, and as large numbers of distributed energy resources and
plug-in electric vehicles (PEVs) are deployed, the automation of
distribution systems becomes increasingly more important to the efficient
and reliable operation of the overall power system.
• The anticipated benefits of distribution grid management include increased
reliability, reductions in peak loads, and improved capabilities for
managing distributed sources of renewable energy.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
NISTNIST Report provides a comprehensiveReport provides a comprehensive
SUMMARY of RELEVANT STANDARDSSUMMARY of RELEVANT STANDARDS
for us to followfor us to follow
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Cited Standards of interestCited Standards of interest (See RED later)(See RED later)
4 DNP3 - This standard is used for substation and feeder deviceautomation as well as for communications between control centers andsubstations.
8 IEEE C37.118 - Synchrophasor Protocol (synchrophasor):
This standard defines phasor measurement unit (PMU) performancespecifications and communications.
9 IEEE 1547 Suite - This family of standards defines physical andelectrical interconnections between utility and distributed generation(DG) and storage. [http://grouper.ieee.org/groups/scc21/dr_shared/]
19 IEEE P2030 Draft Guide for Smart Grid Interoperability of EnergyTechnology and Information Technology Operation with Electric PowerSystem (EPS) and End-Use Applications and Loads.
• Standards, guidelines to be developed by IEEE P2030 Smart GridInteroperability.
23 IEEE C37.2-2008 - IEEE Standard Electric Power System DeviceFunction Numbers - Protective circuit device modeling numberingscheme for various switchgear.
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Cited Standards of interestCited Standards of interest24 IEEE C37.111-199 - IEEE Standard Common Format for Transient
Data Exchange (COMTRADE) for Power Systems (COMTRADE) -Applications using transient data from power system monitoring,including power system relays, power quality monitoring field andworkstation equipment.
26 IEEE 1159.3 - Recommended Practice for the Transfer of PowerQuality Data - Applications using of power quality data.
27 IEEE 1379-2000 Substation Automation - Intelligent ElectronicDevices (IEDs) and remote terminal units (RTUs) in electric utilitysubstations.
38 SAE J1772 - Electrical Connector between PEV and EVSE - Electricalconnector between Plug-in Electric Vehicles (PEVs) and ElectricVehicle Supply Equipment (EVSE)
40 SAE J2847/1-3 - Communications for PEV Interactions; J2847/1Communication between Plug-in Vehicles and the Utility Grid; J2847/2Communication between Plug-in Vehicles and the Supply Equipment(EVSE); J2847/3 Communication between Plug-in Vehicles and theUtility Grid for Reverse Power Flow.
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Other NIST Standards TopicsOther NIST Standards Topics
5.14 Energy Storage Interconnection Guidelines (PAP 07)
What Energy storage is required to accommodate the increasing
penetration of intermittent renewable energy resources and to improve
Electric Power System (EPS) performance. Consistent, uniformly
applied interconnection and information model standards, supported by
implementation guidelines, are required for energy storage devices
(ES), power electronics interconnection of distributed energy resources
(DER), hybrid generation-storage systems (ES- DER), and plug-in
electric vehicles (PEV) used as storage.
Why Due to the initial limited applications of the use of power electronics
for grid interconnection of ES and DER, there are few standards that
exist to capture how it could or should be utilized as a grid-integrated
operational asset on the legacy grid and Smart Grid. For example, no
standards address grid-specific aspects of aggregating large or small
mobile energy storage units, such as Plug-in Electric Vehicles
(PEVs)….
http://collaborate.nist.gov/twiki-sggrid/bin/view/SmartGrid/PAP07Storage.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Other NIST Standards Topics (Other NIST Standards Topics (concon’’dd))5.15 Interoperability Standards to Support Plug-in Electric Vehicles (PAP
11) Interoperability standards that will define data standards to enable the
charging of plug-in electric vehicles (PEVs) will support the adoption of PEVs
and related benefits. Standards are anticipated to be available by the end of
2010.
• [Task 6: Coordinate standards activities for electrical interconnection and safety
standards for chargers and discharging, as well as a weights and standards
certification and seal for charging/discharging. - UL, SAE, IEEE, NEC,NEMA]
http://collaborate.nist.gov/twiki- sggrid/bin/view/SmartGrid/PAP11PEV
7.3 Other Issues to be Addressed This section describes other major
standards-related issues and barriers impacting standardization efforts and
progress toward a fully interoperable Smart Grid.
• 7.3.1 Electromagnetic Disturbances Standards for the Smart Grid should consider
electromagnetic disturbances, including severe solar (geomagnetic) storm risks and
Intentional Electromagnetic Interference (IEMI) threats such as High-Altitude
Electromagnetic Pulse (HEMP).
• 7.3.2 Electromagnetic Interference The burgeoning of communications
technologies, both wired and wireless, used by Smart Grid equipment can lead to
EMC interference, which represents another standards issue requiring study.
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END - NIST ReviewEND - NIST Review
Onto IEEE Standards
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StandardsStandards of Critical Importanceof Critical Importance
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SAE J2293, IEEE P2030 & IEEE 1547SAE J2293, IEEE P2030 & IEEE 1547
IEEE P2030 Smart Grid Interoperability Standards Development Meeting,Jan 26-29, 2010,Detroit Edison, Detroit, MI
SAE J2293
Energy Transfer
System for Electric
Vehicles
IEEE 1547
Interconnection
Standards
IEEE P2030
Smart Grid
Interoperability
Standards
Electrical -
functional
interconnection
between electric
grid and electric
vehicle (two-way
power flow)
Communication,
control and
information (V2G)
Energy transfer
system for
electric vehicles
IEEE P2030 Smart Grid Interoperability Standards Development Meeting
January 26-29, 2010, Hosted by Detroit Edison, Detroit, MI
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1547- 2003 Standard for Interconnecting Distributed Resources
with Electric Power Systems
1547.1 - 2005 Conformance Test Procedures for
Equipment Interconnecting DR with EPS
1547.2 - 2008 Application Guide for IEEE 1547
Standard for Interconnection of DR with EPS
1547.3 - 2007 Guide for Monitoring, Information
Exchange and Control of DR
Current 1547 ProjectsP1547.4 Guide for Design, Operation, and Integration
of DR Island Systems with EPS
P1547.6 Recommended Practice for Interconnecting
DR With EPS Distribution Secondary Networks
P1547.5 Guidelines for Interconnection of Electric
Power Sources Greater Than 10 MVA to the Power
Transmission Grid Urban distribution
networks
Microgrids
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P1547.7 Draft Guide to Conducting Distribution
Impact Studies for Distributed Resource
Interconnection
Identified
in Report
to NIST
!"
IEEE 1547 Interconnection StandardsIEEE 1547 Interconnection Standards
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Distributed
Energy
Technologies
Interconnection
TechnologiesElectric Power
Systems
Fuel Cell PV
MicroturbineWind
Generator
Inverter
Switchgear,
Relays, &
Controls
Functions
• Power Conversion
• Power Conditioning
• Power Quality
• Protection
• DER and Load
Control
• Ancillary Services
• Communications
• Metering
Microgrids
Energy
Storage
Loads
Local
LoadsLoad Simulators
Utility
System
PHEV;
V2G
!#
Distributed Energy Resources InterconnectionDistributed Energy Resources Interconnection
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
IEEE P2030 Smart Grid Interoperability Standards Development Meeting,Jan 26-29, 2010,Detroit Edison, Detroit, MI
IEEE P2030 Smart Grid Interoperability Standards Development Meeting
January 26-29, 2010, Hosted by Detroit Edison, Detroit, MI
P2030 Title: “Guide for Smart Grid Interoperability of Energy Technology and
Information Technology Operation with the Electric Power System (EPS) and
End-Use Applications and Loads”
v. Interconnection
IEEE Standard DevelopmentIEEE Standard Development MeetingMeeting
Scope:
This guide provides a knowledge base addressing
• terminology, characteristics, functional performance and evaluation
criteria, and
• the application of engineering principles for smart grid interoperability of
the electric power system with end-use applications and loads.
The guide discusses alternate approaches to good practices for the
smart grid.
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IEEE P2030 Smart Grid Interoperability Standards Development Meeting,Jan 26-29, 2010,Detroit Edison, Detroit, MI
3 TASK GROUPS for P20303 TASK GROUPS for P2030
9. Power Systems Intraoperability
• 9.1 Energy Sources
• 9.2 Transmission
• 9.3 Substation
• 9.4 Distribution
• 9.5 Load Side
• 9.6 Cyber Security
10. Information SystemsIntraoperability
• 10.1 Introduction, Purpose, andScope
• 10.2 Power Engineering
• 10.3 Architecture
• 10.4 Modeling
• 10.5 Security
• 10.6 Communications
11. Communications SystemsIntraoperability
• 11.1 Purpose and Scope
• 11.2 Models of the Grid
• 11.3 CategorizedCommunications Use Cases
• 11.4 Architectures
• 11.5 Monitoring and ControlIssues
• 11.6 Communication aspects of:Generation, Transmission,Distribution, Microgrids, LoadManagement
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P2030 DraftP2030 Draft
Check the standards DRAFT on
the web.
https://mentor.ieee.org/2030/bp/StartPage
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]!$
1547&P2030 Considerations in NIST 1547&P2030 Considerations in NIST RptsRpts
Energy Storage Systems, e.g., IEEE 1547/2030 extensions for storage
system specific requirements
Distribution Grid Management Initiatives, e.g., extensions of 1547 series
and/or P2030 series, including communications
Voltage Regulation, Grid Support, etc., e.g., develop specifications in
P1547 and/or P2030-series
Management of DER, e.g. Planned island systems
Static and Mobile Electric Storage, including both small and large electric
storage facilities.
Electric Transportation and Electric Vehicles.
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P1809P1809 Electric TransportationElectric Transportation
New Standard committee
First meeting - 18 February 2010
PRESENTATIONS Continuation:
• DOE – Keith Hardy, Grid Interaction Tech Team Lead – 15 minutes
• NREL – Tony Markel, Senior Engineer – 15 minutes
• NIST – Eric Simmon, PAP11 Lead – 15 minute
• SAE – Gery Kissel, Chair SAE J1772 – 10 minutes
• SAE – Rich Scholer, Chair SAE J2847/J2836 -10 minutes
• SAE – Robert Gaylen, Chair SAE Battery Committee – 10 minutes
• APTA – Martin Schroeder, Chief Engineer – 15 minutes
• EEI – Steven Rosenstock, Manager, Energy Solutions - 15 minutes
• NRECA – Andrew Cotter, Senior CRN Program Management Advisor - 10
minutes
• IEEE SA – Mike Kipness, Program Manager, Technical Program Development –
10 minutea
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END - Standards (YEA!)END - Standards (YEA!)
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WhatWhat is the Smart Grid?is the Smart Grid?
How do we survive within the Legacy System?
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What isWhat is the Smart Grid?the Smart Grid?
[EPRI 2006]: “The term ‘Smart Grid’ refers to a modernization of the
electricity delivery system so it
monitors, protects and automatically optimizes the operation of its
interconnected elements—
from the central and distributed generator through the high-voltage
network and
distribution system, to industrial users and building automation systems,
to energy storage installations and to end-use consumers…”
Our discussion is from Sub-Transmission to the Meter
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Structure of Interest in a NutshellStructure of Interest in a Nutshell
Picture from: http://www.peco.com/pecores/customer_service/the_electric_system.htm
(1) & (2): Generation step-up to Transmission !115kV
(2): Flow is regulated by ISOs (Independent System Operators)
(2): General contrast between NE v. W -- Mesh v. Point-to-Point
(3) Distribution is "12kV
(12.47kV or 7,200V L-N)
(3) thru (4)
ARE MAIN FOCUS
(4) Local distribution is "4.8kV
down to 120V (4,160V or
2400 L-N)
TRANSFORMERS AND PROTECTION ARE OF MAIN INTEREST
Distribution transformer is on the pole;
Substation transformer is on the ground in the Distribution Substation/Switch Yard
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“Traditionally,” system stability is
part of transmission
Major resource for information is
the IEEE “Red Book”
“Local distribution” is considered
240V/480V
Focus on "12kV system, know
nuances of requirements and how
PElect can include protection.
Distribution
Substation
Sub-Transmission
Substation
Transmission
!115kV
5 to 20 MVA
(or higher)
See “Red Book”
12kV
Industrial
Loads
Alternative
Energy
Sources
e.g. 4800k
(in NY)
Structure of Interest in a Nutshell (Structure of Interest in a Nutshell (concon’’dd))
Breaker protects
transformer
Breaker protects
cabling
Some disconnects
can open under load
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Voltage RangesVoltage Ranges (ANSI C84.1 Standard) (ANSI C84.1 Standard)
Are
as o
f in
tere
st
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A Test Bed for Smart PowerA Test Bed for Smart Power
DevelopmentDevelopment
The Intelligent Substation
Proposed test bed at the University at Buffalo
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
From: N.Mohan, “First Course on Power Electronics, 2005
Power Electronic ApplicationsPower Electronic Applications
Distributed generation (DG)
• Renewable resources (wind and photovoltaic)
• Fuel cells and micro-turbines
• Storage: batteries, super-conducting magnetic energy storage, flywheels
Power electronics loads: Adjustable speed drives
Power quality solutions
• Dual feeders
• Uninterruptible power supplies
• Dynamic voltage restorers
Transmission and Distribution (T&D)
• High voltage dc (HVDC) and medium voltage dc
• Flexible AC Transmission Systems (FACTS): Shunt and Series
compensation, and the unified power flow controller
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Site DevelopmentSite Development Smart Distribution Smart Distribution SystSyst
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Development Platform-Development Platform-The Intelligent Substation
•Campus-integrated
•34.5kV dual feeds
•Multiple dist voltages
•Multiple renewables
• (50kW levels)•AC & DC dist
•Circular pwr flow
•Advanced controls
• (Neural network ctrl)
•Environ. testing
Technology Areas:Technology Areas:
1. Distributed Generation – Green Power Conversion
2. Automation & Control – Artificial Neural Networks
3. Intelligent Sensors & Networks – Wired & Wireless
4. System Protection – AC/DC and FACTS systems
5. Energy Storage – Electrochemical, Electromechanical
6. Residential EMS [Energy Management Systems]7. Interoperability between the Old & the New
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Utility ApplicationsUtility Applications
Distributed Generation (DG) Applications
AC
DC
DC
AC
Wound rotor
Induction Generator
Generator-side
Converter
Grid-side
Converter
Wind
Turbine
Isolated
DC-DC
Converter
PWM
Converter
Max. Power-
point Tracker
Utility
1f
Wind Power Generation with
Doubly Fed Induction Motors
Photo-voltaics Interface
From: N.Mohan, “First Course on Power Electronics, 2005
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Utility ApplicationsUtility Applications ( (concon’’dd))
Power Quality Solutions for
• voltage distortion
• unbalances
• voltage sags and swells
• power outages
Dual Feeders
Power Electronic
InterfaceLoad
Dynamic Voltage Restorers (DVR)
Uninterruptible Power
Supplies
Rectifier Inverter FilterCritical
Load
Energy
Storage
From: N.Mohan, “First Course on Power Electronics, 2005
Feeder #1
Feeder #2
Solid State
Switches
LOAD
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Utility ApplicationsUtility Applications ( (concon’’dd))
Transmission and Distribution: DC Transmission
• most flexible solution for connection of two ac systems
AC1 AC2
HVDC
AC1 AC2
MVDC
From: N.Mohan, “First Course on Power Electronics, 2005
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Background - T&D Systems and FACTSBackground - T&D Systems and FACTS
Stability
Power flow controlDirectional routing
Quality control
Power conversion (MVDC)
What control is needed in the power syst?
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Power and Control SensitivityPower and Control Sensitivity
Starting with Transmission Model…
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Transmission Line ModelsTransmission Line Models
Parameters of distributed inductance, capacitance and resistance
precisely define the “overhead” transmission line. However, for short
lines a simpler model can be used.
Three models estimate the transmission line
Short Lines < 50 mi. – only a series impedance
50< Medium Lines < 250mi – uses singular lumped parameters
250mi.< Long Lines – uses distributed parameters
Short lines are typically represented by inductance only. Resistance can
be lumped with the load.
Depending on system cost, reliability and location “CABLING” is used.
[Cabling is not included in this seminar]
Distribution Lines
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General power flow - simple lineGeneral power flow - simple line
Eg / ! VB / 0
jXB
+ I -
!
If " # $Eg %$VB Find : Power to control
SB = PB + jQB = VB • I * , (receiving end)
!
r I = Eg"# $VB"0( ) jX B( )r I = Ege
j # $90o( )$VB e
j 0$90o( )%
& '
(
) * X B
r I + = Ege
$ j # $90o( )$VB e
$ j 0$90o( )%
& '
(
) * X B
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Computing power Computing power transfered transfered (flow)(flow)
!
Remember : SB = PB + jQB = VB • I *
SB = VB Ege+ j 0"# +90
o( )"VB
2e+ j 0"0 +90
o( )$
% &
'
( ) X B
= jVB Eg cos("# )+ j sin("# ){ } " jVB2[ ] X B
!
cos("# ) = cos(+# ); j cos(# ) = sin(# ); j sin("# ) = " j sin(+# ) = cos(# )
!
Therefore :
SB = VB Eg sin(" )+ jVB Eg cos(" )# jVB2[ ] X B
P jQ
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Real and Real and Quadrature Quadrature PowerPower
!
Real Power (P) :
P =VB Eg
X B
sin(" )#
$ % %
&
' ( ( P
ow
er[W
]
![rad]
!
SB = PB + jQB
Quad P
ow
er[V
AR
s]
![rad]
!
Quadrature Power (QB ) :
jQB =
j VB Eg cos(" )#VB( )$ % &
' ( )
X B
= jVB Eg
X B
cos(" )#VB
2
X B
$
% & &
'
( ) )
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
• Influence the magnitude of the voltage from the source.
• Influence the line reactance.
• Influence the magnitude of the load bus voltage.
• Influence the angle, !2, of the load. (! = / Eg - / VB )
How can you change power flow?How can you change power flow?
Eg / ! VB / 0
jXB
+ I -
!
Real Power (P) :
P =VB Eg
X B
sin(" )#
$ % %
&
' ( (
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Introduction to FACTSIntroduction to FACTS ControllersControllers
Conceptual overview of controllers
and how they can be used.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Helping in power managementHelping in power management
• Control of power flow as ordered, ensure optimum flow, redirect flow
during emergencies, increase utilization of lowest cost generation, etc.
• Increase dynamic line loading to thermal limits adjusted for seasonal
and environmental conditions, and according to loading history.
• Increase transient stability, limit short-circuit currents and overloads,
manage cascading blackouts, and dampen electromechanical and sub-
synchronous resonances.
• Provide secure tie line connections to neighboring utilities and regions
thereby decreasing overall generation reserve requirements on both
sides.
• Reduce reactive power flows and loop flows, allowing the lines to carry
more active power.
• Provide greater flexibility in siting new generation, upgrading lines, etc.
Controllers help distribution and transmission owners to:
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
General placementGeneral placement
Series controller
Inter-tie controller
Shunt controller
DCw/ storage
DC
dc link
Unified series-shunt controller
(w, w/o storage)
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Alphabet soup for the controllers -Alphabet soup for the controllers - these are thethese are the
definitions from the IEEE working groupdefinitions from the IEEE working group
Part I - SHUNT CONTROLLERS
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Shunt controller
- voltage source
Shunt controller
- current source
Static Synchronous CompensatorStatic Synchronous Compensator
Static synchronous generator
operated as a shunt-connected static
VAR compensator whose capacitive
or inductive output current is
controlled.
STATCOM is one of the key FACTS
Controllers and based on voltage-
source converters (VSCs) or current-
source converters. The VSCs are
more cost effective and preferred.
The capacitor voltage is
automatically adjusted as required to
serve as a voltage source for the
converter.
STATCOMs can be designed to also
act as an active filter to absorb
system harmonics.
(STATCOM)(STATCOM)
Bi-D
irect
iona
l con
v.
<v>=0
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Static Synchronous Generator (SSG)Static Synchronous Generator (SSG)
A self-commutated switching power
converter supplied from an
appropriate electric energy source
and operated to produce a set of
adjustable multiphase output
voltages, which may be coupled to
an ac power system for the purpose
of exchanging independently
controllable real and reactive power.
•SSG is a combination of STATCOM
and energy source
•Supplies or absorbs power
Shunt controller
- voltage source
interface converter
energystorage
•May use
•battery (Battery Energy Storage System (SSG-BESS)),
•flywheel,
•superconducting magnet (Magnetic Energy Storage (SSG-SMES)),
•large dc storage capacitor, another rectifier/inverter, etc.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Static VAR Compensator (SVC)Static VAR Compensator (SVC)
A shunt-connected static var generator or absorber whose output is
adjusted to exchange capacitive or inductive current so as to maintain
or control specific parameters of the electrical power system
A.K.A.: thyristor-controlled or thyristor-switched reactor for absorbing
reactive power, and/or thyristor-switched capacitor for supplying the
reactive power, or combination
SVC is based on simple SCRs and considered by some as a lower cost
alternative to STATCOM, although this may not be the case if the
comparison is made based on the required performance and not just
the MVA size.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
SVC-Thyristor Controlled Reactor (TCR)SVC-Thyristor Controlled Reactor (TCR)
A shunt-connected, thyristor-
controlled inductor whose
effective reactance is varied in a
continuous manner by partial-
conduction control of the thyristor
•TCR is a subset of SVC in which
conduction time and hence,
current in a shunt reactor,
controlled by a thyristor-based ac
switch with firing angle controlSVC-TCR, Thyristor
Controlled Reactor
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
SVC-Thyristor Switched Reactor (TSR)SVC-Thyristor Switched Reactor (TSR)
A shunt-connected, thyristor-
switched inductor whose effective
reactance is stepwise varied by
full- or zero-conduction operation
of the thyristor.
•TSR is made up of several shunt
connected inductors switched in
and out by thyristors
•Controls achieve step changes
in the reactive power consumed
from the system.
•Use of thyristor switches without
firing angle control results in
lower cost and losses, but without
a continuous control.
SVC-TSR, Thyristor
Switched Reactor
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
SVC-Thyristor Switched Cap (TSC)SVC-Thyristor Switched Cap (TSC)
A shunt-connected, thyristor-
switched capacitor set whose
effective reactance is stepwise
varied by full- or zero-conduction
operation of the thyristor.
•Thyristors switch shunt
capacitors units in and out
(without firing angle control) to
achieve step changes in the
reactive power supplied to the
system.
•Unlike shunt reactors, shunt
capacitors cannot be switched
continuously with variable firing
angle control.
SVC-TSC, Thyristor
Switched Capacitor
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Static VAR Gen. or AbsorberStatic VAR Gen. or Absorber
A static electrical device, equipment, or system capable of drawing
controlled capacitive and/or inductive current from an electrical power
system, thereby generating or absorbing reactive power. Generally
considered to consist of shunt-connected, thyristor-controlled reactor(s)
and/or thyristor-switched capacitors.
Both the SVC and the STATCOM are static VAR generators equipped
with appropriate control loops to vary the VAR output so as to meet
specific compensation objectives.
Static VAR System (SVS)Static VAR System (SVS)A combination of different static and mechanically-switched VAR
compensators whose outputs are coordinated.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Thyristor Thyristor CtrlCtrl’’d d Braking Resistor (TCBR)Braking Resistor (TCBR)
A shunt-connected thyristor-
switched resistor to aid
stabilization of a power system or
to minimize power acceleration of
a generating unit during a
disturbance.
•TCBR involves cycle-by-cycle
switching of a resistor with
thyristor-based firing angle
control
•Can be utilized to selectively
damp low-frequency oscillations.
SVC-TCBR, Thyristor
Switched Braking Resistor
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Alphabet soup for the controllers - these are theAlphabet soup for the controllers - these are the
definition from the IEEE working groupdefinition from the IEEE working group
Part II - Series Controllers
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Static Sync. Series Compensator (SSSC)Static Sync. Series Compensator (SSSC)
A static synchronous generator operated without an external electric
energy source as a series compensator whose output voltage is in
quadrature with the line current for increasing or decreasing overall
reactive voltage drop across the line
The SSSC may include transiently rated energy storage or absorbing
devices to enhance the dynamic response by temporary addition of real
power to increase or decrease the overall real (resistive) voltage drop
across the line.
• SSSC is one the most important FACTS Controllers. It is like a
STATCOM, except that the output ac voltage is in series with the line.
• It can be based on a VSC or current-sourced converter.
• Battery-storage or superconducting magnetic storage can be added to
inject a voltage vector of variable angle in series with the line.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Interline Power Flow Controller (IPFC)Interline Power Flow Controller (IPFC)
New/possible definition: Combination
of two or more SSSCs coupled via a
common dc link to facilitate bi-
directional flow of real power
between the SSSCs, and are
controlled to provide independent
reactive compensation in each line.
The IPFC structure may also include
a STATCOM, coupled to the IPFC's
common dc link, to provide shunt
reactive compensation and supply or
absorb the overall real power deficit
of the combined SSSCs.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Alphabet codeAlphabet code
R(Reactor)
S(Switched)
C(Capacitor)
S(Series)
C(Controlled)
T(Thyristor)
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
TCSC, Thyristor
Controlled Series
Capacitor
Thyristor Thyristor CtrlCtrl’’d d Series Capacitor (TCSC)Series Capacitor (TCSC)
Capacitive reactance compensator
consisting of a series capacitor bank
shunted by a thyristor-controlled
reactor (TCR) to provide smoothly
variable series capacitive reactance.
The TCSC uses SCRs
When the TCR firing angle is 180º,
the reactor is non-conducting and the
series capacitor has normal
impedance. As the firing angle is
advanced from 180º, the capacitive
impedance increases
When the TCR firing angle is 90, the
reactor becomes fully conducting,
and the total impedance becomes
inductive
MOST COMMON
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
TCSC, Thyristor
Controlled Series
Capacitor
Thyristor-Sw. Series Capacitor (TSSC)Thyristor-Sw. Series Capacitor (TSSC)
Capacitive reactance
compensator consisting of a
series capacitor bank shunted by
a thyristor-switched reactor to
provide stepwise control of series
capacitive reactance.
Switches inductors at firing angle
90º or 180º without firing angle
control to reduce cost and losses
of the Controller
Could combine thyristor control,
and thyristor switching.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Thyristor-CtrThyristor-Ctr’’d d Series Reactor (TCSR)Series Reactor (TCSR)
An inductive reactance
compensator consisting of a
series reactor shunted by a
thyristor controlled reactor to
provide a smoothly variable
series inductive reactance.
When the firing angle of the
thyristor controlled reactor is 180º
degrees, it stops conducting, and
the uncontrolled reactor acts as a
fault current limiter
As the angle decreases, the net
inductance decreases until firing
angle of 90º, when the net
inductance is the parallel
combination of the two reactors.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Thyristor-Sw. Series Reactor (TSSR)Thyristor-Sw. Series Reactor (TSSR)
:An inductive reactance
compensator consisting of a
series reactor shunted by a
thyristor switched reactor to
provide stepwise control of series
inductive reactance.
This is a complement of TCSR,
but with thyristor switches fully on
or off (without firing angle control)
to achieve a combination of
stepped series inductances
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Alphabet soup for the controllers - these are theAlphabet soup for the controllers - these are the
definition from the IEEE working groupdefinition from the IEEE working group
Part III - Combined Shunt and Series
Controllers
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Unified Power Flow Controller (UPFC)Unified Power Flow Controller (UPFC)
A combination STATCOM and SSSC
coupled via a common dc link (for
bidirectional flow of real power
between the two) and are controlled
to provide concurrent real and
reactive series line compensation
without an external electric energy
source.
The UPFC is able to control the
transmission line voltage,
impedance, and angle or,
alternatively, real and reactive power
flow in the line.
The UPFC may also provide
independently controllable shunt
reactive compensation.
Additional dc storage, can provide
further effectiveness
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
(TCPST)(TCPST)A phase-shifting transformer
adjusted by thyristor switches to
provide a rapidly variable phase
angle.
Phase shifting is obtained by
adding a perpendicular voltage
vector in series with a phase.
The vector is derived from the
other two phases via shunt
connected transformers.
Thyrst-CtrlThyrst-Ctrl’’d d Phase Shifting Phase Shifting TfrmrTfrmr
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Interphase Interphase Power Controller (IPC)Power Controller (IPC)
A series-connected controller in
each phase of inductive and
capacitive branches subjected to
separately phase-shifted
voltages.
The active and reactive power
can be set independently by
adjusting the phase shifts and/or
the branch impedances, using
mechanical or electronic
switches.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Thyristor-CtlThyristor-Ctl’’d d Voltage Limiter (TCVL)Voltage Limiter (TCVL)
A thyristor-switched metal-oxide
varistor (MOV) used to limit the
voltage across its terminals
during transient conditions.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Thyristor-CtrlThyristor-Ctrl’’d d Volt. Regulator (TCVR)Volt. Regulator (TCVR)
A thyristor-controlled transformer
which can provide variable in-
phase voltage with continuous
control.
Uses a transformer with thyristor-
controlled tap changing or
Thyristor-controlled ac-ac
converter for injection of variable
ac voltage of same phase in
series with the line
Such a relatively low cost
controller can effectively control
the flow of reactive power
between two ac systems.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Technical ReviewTechnical Review & Discussion -& Discussion -
Concept DevelopmentConcept Development
Brief Discussion of:
• Symmetrical Components
• Harmonics
• Power Control
• Power Flow
[FURTHER SLIDES ON TOPIC OMMITTED]
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Symmetrical ComponentsSymmetrical Components
- CONCEPT ONLY-- CONCEPT ONLY-
An easy method to understand unbalanced
system operation is through
Symmetrical Components
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Characteristics:
• System must be linear for superposition of Components
• All waves in Symmetrical Components are single-frequency sinusoids
• Symmetrical Components can be combined with Fourier Analysis to
understand harmonic effects and wave distortion.
The key idea of Symmetrical Component analysis is to decompose the
system into three sequence networks. The networks are then coupled
only at the point of the unbalance (e.g., the fault)
The three sequence networks are known as the: Positive Sequence,
Negative Sequence and Zero Sequence
To Analyze Unsymmetrical Systems:To Analyze Unsymmetrical Systems:
1. Use direct network calculations or circuit simulation, or
2. Use “Symmetrical Coordinates” as proposed by Charles L. Fortescue
[AIEE Transactions, V37 Part 2, 1918], now know as “Symmetrical
Components”
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Concept of Symmetrical ComponentsConcept of Symmetrical Components
We already understand how to map a general vector into two orthogonal
vectors that are on real and imaginary axes.
Now consider a set of three general phasors each having a unique
magnitude and phase. These can be mapped onto a set of symmetrical
phasors, not all uniquely defined.
Re
Im120°
120° 120°
Voltage of Current
PhasorPhasors with Symmetrical Components
Positive
sequence
Negative
sequence
Zero
sequence
a
a
b
c
b
c
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Sequence Set RepresentationSequence Set Representation
Any arbitrary set of three phasors, say Ia, Ib, Ic, and each having a
unique magnitude and phase (but all with same frequency) can be
represented as a sum of the three sequence sets
!
Ia
= Ia
0+ I
a
++ I
a
"
!
Ib
= Ib
0+ I
b
++ I
b
"
!
Ic
= Ic
0+ I
c
++ I
c
"
The symmetrical components are:
!
I a+
,I b+
,I c+ are positive sequence set
I a"
,I b"
,I c" are negative sequence set
I a0
,I b0
,I c0 are zero sequence set
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Background UnderstandingBackground Understanding
- CONCEPT ONLY-- CONCEPT ONLY-
Brief Discussions:
Harmonics and Fourier Series, Harmonic Power and
THD, Per Unit System
Not in notes
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Harmonics (i.e. Fourier Series)Harmonics (i.e. Fourier Series)
Fundamentally important for power quality, harmonic
control and high frequency design
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
The BasicsThe Basics
Any physically realizable periodic function, f(t) = f(t+T), (for period T) can
be written as a sum of sinusoids:
where the sum is taken over n=1 to infinity, ! = 2"/T,
However, there is an easier view for conceptualization….
!
f t( ) = a0 + an cos nwt( ) + bn sin nwt( )[ ]n=1
"
#
Time varying sinusoids displaced by 90˚
Magnitudes for each sinusoid
Note: for “even symmetry” about the y axis, bn = 0 ;
for “odd symmetry” about the origin, an=0
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
The BasicsThe Basics
Any physically realizable periodic function, f(t) = f(t+T), (for period T) can
be written as a sum of sinusoids:
where the sum is taken over n=1 to infinity, ! = 2"/T,
However, there is easier view for conceptualization
!
f t( ) = a0 + an cos nwt( ) + bn sin nwt( )[ ]n=1
"
#
!
a0 : Average of f t( ) = f t( )
!
a0 =1
Tf t( )dt
"
" +T
#
!
an =2
Tf t( ) cos nwt( )dt
"
" +T
#
!
bn =2
Tf t( ) sin nwt( )dt
"
" +T
#
!
" = 2# $ freq , freq = 1T
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Each cosine term, cn cos(n!t + "n), is called a Fourier Component or a
Harmonic of the function f(t) with “n” harmonics.• cn is the “amplitude” component;
• "n is the component phase;
• c0 = a0 is the dc component, the average value of f(t), c0 = <f(t)>.
Polar Form (best for conceptualization)Polar Form (best for conceptualization)
We can also write
The term c1 cos(!t + "1) is the “fundamental” of f(t), while 1/T is the
fundamental frequency.
In power, we seek a single desired frequency
!
f t( ) = cn cos n"t +#n( )n=0
$
%"= "
n
n
na
b1tan#
+=
==
nnnbac
ac
22
000 0#,
Of most interest
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Harmonics in CircuitsHarmonics in Circuits
A non-sinusoidal source can be decomposed into Fourier Components
Each component can be individually applied to the same “LINEAR”
circuit, and through “superposition,” the effects of each component
individually evaluated.
Harmonic Superposition is a major concept for switching circuits
v(t)
v1(t)
v2(t)
v0
XL(f) XC(f)
v3(t)
http://www.ipes.ethz.ch/
http://www.ipes.ethz.ch/ipes/pfc/e_fourier.html
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
!
pavg ="
2#vnim cos( n"t +$n )cos( m"t +%m )dt
0
2 #"&
m=0
'
()
*
+ +
,
-
.
. n=0
'
(
What about Harmonic Power?What about Harmonic Power?
!
v t( ) = vn
cos n"t +#n( )$
!
i t( ) = im
cos m"t +#m( )$
Assume a voltage
and a current
with the same base frequency !.
+
"
v(t)
i(t)
ENERGY
!
p t( ) = v t( ) " i t( )
!
= vn cos()"[ ] im cos()"[ ]
!
pavg ="
2#$ $[ ]
0
2#"% dt
What is the “power” flow in the circuit?
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
!
pavg = 1 2 4 4 3 4 4 m=0
"
#$
%
& &
'
(
) )
n=0
"
#
!
Pavg = v0i0 +vnin
2 2cos("n #$n )
n=1
%
& = VnRMS I n
RMS cos("n #$n )
n=0
%
&
Average PowerAverage Power
IMPORTANT: ONLY “same-frequency” harmonics yield REAL power.
Cross-frequency harmonics contribute REACTIVE power along with
reactive components.
!
"
2#vnim cos( n"t +$n )cos( m"t +%m )dt
0
2#"&
!
"
2#( )dt
0
2#"$ =
0 , m % n
vnim cos(&n '(m )
2, n = m % 0
vnim , n = m = 0
)
* +
, +
CRITICAL
TAKE-AWAY!
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Harmonic DistortionHarmonic Distortion
DISTORATION - If you only need a single frequency
out, such as zero frequency, then what are the other
frequencies doing for you?
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Harmonics Harmonics w/ w/ Duty Cycle Duty Cycle variationvariation
1
0
DT
t0
t0+T
f(t)
!
f t( ) =1, ...
0 , ...
" # $
!
a0 =1
Tf ( t )dt
t0
T + t0
" =DT
T= D
!
an =2
Tf ( t ) cos( n"t )dt
t0
T + t0
# = ...
!
OR cn =2
"
sin( n"D )
n, n # 0
Fourier series of “generic” f(t)
!
f t( ) = D +2
"
sin n"D( )n
cos n#t $%n( )n=1
&
'
!
"n
= n#t0
Harmonics of a Rectangular Signal with Duty Cycle(http://www.ipes.ethz.ch/ipes/signalHarmo/e_harmo.html)
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Distortion is Fundamental to SwitchingDistortion is Fundamental to Switching
There will always be unwanted terms. A switching converter does
not produce perfect waveforms (ac or dc).
How much of the signal is harmonic?
Total harmonic distortion (THD) measures the distortion content as
a fraction of the fundamental.
!
THD =
cn
2
n= 2
"
#
c1
2
!
IRMS
=1
2c
n
2
n=1
"
# $ THD =
IRMS
2 % IRMS
2
n=1
IRMS
2
n=1
To use the RMS value:
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Per Unit SystemPer Unit System of Calculationsof Calculations
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Three-Phase Per Unit SystemThree-Phase Per Unit System
1. Pick 3-ph bases for system: use L-L voltage,VB,LL, and complex
power, SB,3ø [VA]. (Often nameplate transformer data.)
2. Reflect the voltage base through the transformers, i.e. different
voltage bases – VB, all L-L. (Power passes directly.)
3. Calculate the impedance base
Note - same impedance base as single phase!
Procedure is similar to 1-ph except we use a 3-ph VA base, and use
Line-to-Line voltage base. Always assume a balanced system.
2 2 2, , ,
3 1 1
( 3 )
3
B LL B LN B LN
B
B B B
V V VZ
S S S! ! !
= = =
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Three Phase Per Unit, cont'dThree Phase Per Unit, cont'd
4. Calculate the current base, IB
Same current basis as with single phase.
Convert actual values to per unit
3 1 13 1B B
, , ,
3I I
3 3 3
B B B
B LL B LN B LN
S S S
V V V
! ! !! != = = =
© 2003 Tom Overbye, University of Illinois at Urbana-Champaign,All Rights Reserved
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Electric Power DistributionElectric Power Distribution
and Utilization Standardsand Utilization Standards
Primary information comes from the IEEE Color Books
Distribution Topics are primarily
from the “Red Book”
ANSI/IEEE - Std. 141-1993
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The IEEE Color BooksThe IEEE Color Books
IEEE Std 141-1993: Recommended Practices for Electric Power
Distribution for Industrial Plants [RED]
IEEE Std 142-1991: Recommended Practice for Grounding of Industrial
and Commercial Power Systems [GREEN]
IEEE Std 241-1990: Recommended Practice for Power Systems in
Commercial Buildings [GRAY]
IEEE Std 242-1986: Recommended Practice for Protection and
Coordination of Industrial and Commercial Power Systems [BUFF]
IEEE Std 399-1990: Recommended Practice for Industrial and
Commercial Power System Analysis [BROWN]
IEEE Std 446-1987: Recommended Practice for Emergency & Standby
Power Systems for Industrial & Commercial Applications [ORANGE]
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IEEE Std 493-1990IEEE Std 493-1990: Recommended Practices for the Design of Reliable
Industrial & Commercial Power Systems [GOLD][GOLD]
IEEE Std 602-1986IEEE Std 602-1986: Recommended Practices for Electric Systems in
Healthcare Facilities [WHITE][WHITE]
IEEE Std 739-1984: Recommended Practices for Energy Conservation
and Cost Effective Planning in Industrial Facilities [BRONZE]
IEEE Std 1100-1992: Recommended Practices for Powering and
Grounding Sensitive Electronic Equipment [EMERALD]
The IEEE Color BooksThe IEEE Color Books
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NATIONAL STANDARDSNATIONAL STANDARDS
USA
ANSI- American National Standards Institute.
NIST- National Institute of Standards & Technology
ASTM- American Society for Testing & Materials.
EEI- Edison Electric Institute [Trade Assn. of Private Utilities].
EPRI- Electric Power Research Institute.
IEEE- Institute of Electrical & Electronics Engineers.
Mil.- Military – Department of Defense.
NEMA- National Electrical Manufacturers Association.
NFPA- National Fire Protection Association NEC
OSHA- Occupational Safety & Health Administration
UL- Underwriters Laboratories, Inc. [Safety Standards].
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INTERNATIONAL STANDARDSINTERNATIONAL STANDARDS
CANADA
CSA- Canadian Standards Association.
GERMANY
VDE- Verbandef Deutscher Elektrotechniker.
INTERNATIONAL (Headquarters- Geneva, Switzerland).
IEC- International Electrotechnical Commission
ISO- International Standards Organization.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Placement of Transformers & Breakers-Placement of Transformers & Breakers-Understanding System-LevelUnderstanding System-Level Deployment ProblemsDeployment Problems
Solid State Transformers (SSTs) and Solid State Circuit
Breakers* (SSCBs) will need to co-exist with magnetic
transformers and electromechanical breakers
Legacy systems must be understood and included in
the early phase of system planning and part of the
equipment design process when developing new
apparatus.
*see next page
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
SSCB v. SSPCSSCB v. SSPC
The “Solid State Circuit Breaker” (SSCB) is typically considered to have a
simple open and closing function when activated, and can open under
fault.
The “Solid State Power Controller” (SSPC) is typically considered to have
included current sensing, and fault current profiling including possible
current limiting. SSPCs are not typically associated with power
distribution because of the lower power levels of operation.
In this seminar the SSCB will include reference to SSPCs also.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Placement in Simple Radial SystemPlacement in Simple Radial System
Transformer
• Has predicable source as do the circuit breakers
Breakers
• The right side breakers are typically thought to be molded case, self
contained breakers.
• The left side breaker is directly controlled as part of the protection scheme
Simple RADIAL System
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Placement in Simple Ring Bus SystemPlacement in Simple Ring Bus System
Ring Bus System (v. Radial) - Found in denser load areas
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Placement in SelectivePlacement in Selective SystemSystem
Primary Selective Radial System
Transformers
• Fed from either feeder, but
with predictable load
Breakers (no special issues)
Secondary Selective Radial Syst.
Transformers (no special issues)
Breakers (no special issues)
Protecting
Xfrmr
Protecting
Cabling
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Primary Loop Radial System -• Similar to Primary Selective Radial System
Placement in SelectivePlacement in Selective SystemSystem ( (concon’’dd))
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Load Expansion AlternativesLoad Expansion Alternatives
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Load Expansion AlternativesLoad Expansion Alternatives ( (concon’’dd))
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Standards - Voltage RangesStandards - Voltage Ranges
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ANSI C84.1 standardANSI C84.1 standardThe American National Standard Institute (ANSI) has developed the
Standard C84.1 which is designed to establish nominal voltage ratingsand operating tolerances for 60-hertz electric power systems between100V and 230kV. The purposes of the ANSI C84.1 standard are to :
Promote a better understanding of the voltages associated with powersystems and utilization equipment to achieve overall practical andeconomical design and operation.
Establish uniform nomenclature in the field of voltages
Promote standardization of nominal system voltages and ranges ofvoltage variations for operating systems
Promote standardization of equipment voltage ratings and tolerances
Promote coordination of relationships between system and equipmentvoltage ratings and tolerances
Provide a guide for future development and design of equipment toachieve the best possible conformance with the needs of the users
Provide a guide, with respect to choice of voltages, for new power systemundertakings and for changes in old ones.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
550, 575600
440480
460Y/265480Y/277
230, 250240
240/120
216Y/125208Y/120
110, 115, 125120
110/220, 115/230, 125/250120/240
Associated nonstandard System
Voltages
Standard Nominal System Voltages
Standard Voltages - Low VoltagesStandard Voltages - Low Voltages
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
66 00069 000
44 00046 000
33 00034 500
34 500Y/19 920
24 940Y/14 400
23 000
22 860Y/13 200
20 780Y/12 000
13 800
14 40013 800Y/7970
13 200
13 200Y/7620
12 470Y/7200
12 000Y/6930
11 000, 11 5008320Y/4800
6600, 72006900
46004800
40004160
4160Y/2400
2200, 23002400
Associated nonstandard System VoltagesStandard Nominal System Voltages
Standard Voltages - Medium VoltagesStandard Voltages - Medium Voltages
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
220 000230 000
154 000161 000
132 000138 000
110 000, 120 000115 000
Associated nonstandard System
Voltages
Standard Nominal System Voltages
765 000
500 000
345 000
Associated nonstandard System
Voltages
Standard Nominal System Voltages
Standard Voltages - High VoltagesStandard Voltages - High Voltages
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Ranges A & BRanges A & B
Range A :
Service Voltage : Electric supply systems shall be so designedand operated that most service voltages will be within thelimits specified for Range A. The occurrence of servicevoltages outside of these limits should be infrequent.
Utilization Voltage : Electrical systems shall be designed andoperated within the voltage range defined as Range A; whichmost utilization voltages being specified within this range.
Utilization equipment shall be designed and rated to givefully satisfactory performance throughout range A.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Range ARange A & B& B
Range B :
Service and Utilization Voltage: Range B includes voltagesabove and below Range A limits that necessarily result frompractical design and operating conditions on supply or usersystems, or both. Although such conditions are a part ofpractical operations, they shall be limited in extent, frequency,and duration. When they occur, corrective measures shall beundertaken within a reasonable time to improve voltages tomeet Range A requirements.
Insofar as practicable, utilization equipment shall be designed togive acceptable performance in the extremes of the range ofutilization voltages, although not necessarily as goodperformance as in Range A.
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Range of RangesRange of Ranges
copyrighted by IEEE
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Flicker (IEEE Std 141-1993)Flicker (IEEE Std 141-1993)
copyrighted by IEEE
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System Protection -System Protection -
SSSSTransformer Transformer and SSCB Requirementsand SSCB Requirements
The SST and SSCB will need to open under full fault
current and perform in legacy systems as traditional CB
operate. A set of metrics are given as guide to Smart
Breaker development
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Fundamental considerationsFundamental considerations
Reliability- Denotes certainty of correct operation together with assurance
against incorrect operation from all extraneous causes.
Speed – to obtain the minimum fault clearing time and damage to
equipment.
Selectivity – Complete selectivity being obtained when a minimum
amount of equipment is removed from service for isolation of a fault or
other abnormality.
Economics – Maximum protection at minimum cost.
IEEE Std 242-2001, Recommended Practice for Protection and Coordination of Industrialand Commercial Power Systems (IEEE Buff Book)
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Analysis of System and ProtectionAnalysis of System and Protection
Even with the best design possible, materials deteriorate and the
likelihood of faults increases with age.
Operating records show that the majority of electric circuit faults originate
as phase-to-ground faults.
In grounded systems, phase-to-ground faults produce currents of
sufficient magnitude for detection by ground-fault responsive
overcurrent relays.
If the system neutral is grounded through a proper impedance, the value
of the ground-fault current can be restricted to a level that would avoid
extensive damage at the point of the fault, yet adequate for ground-
fault relaying.
In ungrounded systems, phase-to-ground faults produce relatively
insignificant values of fault current. In small installations, with isolated
neutral, the ground-fault current for a single line-to-ground fault may be
well under one ampere. Overcurrent relays are not generally used to
detect and isolate this low current fault.
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Distortion of Phase V & I During FaultsDistortion of Phase V & I During Faults
copyrighted by IEEE
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Normal and 3-ph faultNormal and 3-ph fault
copyrighted by IEEE
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SeveralSeveral types of faultstypes of faults
copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
IEEE_Std_C37.2._2008
Some types of Circuit BreakersSome types of Circuit Breakers
Overcurrent relays;
Overcurrent relays with voltage
restraint or voltage control;
Directional relays;
Differential relays;
Current balance relays;
Ground-fault relays;
Synch-check and synchronizing
relays;
Pilot-wire relays;
Voltage relays;
Distance relays;
Phase-sequence or reverse-
phase relays;
Volts/Hz over-excitation relays;
Frequency relays;
Temperature-sensitive relays;
Pressure-sensitive relays;
Replica-type temperature relays;
Auxiliary relays;
Direct-acting trip devices for low-
voltage power circuit breakers;
Power fuses
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Time-CurrentTime-Current (typical time(typical time-1-1 OC OC Relay)Relay)
copyrighted by IEEE
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Typical Electro-MechanicalTypical Electro-Mechanical
Solid State is much
faster. However, the
system must be
compatible with faster
response times.
copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Typical Typical t-I t-I plot for SS Trip Deviceplot for SS Trip Device
copyrighted by IEEE
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Impulse Voltage Withstand RequirementsImpulse Voltage Withstand Requirements
New standards and system requirements may be
needed for power electronics equipment to
economically withstand transient over-voltages
Surge voltages occur from, e.g. lightning and the
reflections from the resultant traveling waves
Cabling becomes more of a challenge
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
When wavelengths are short compared to the physical length of
circuitry, then it may be necessary to use “distributed-constant”
representation
Surge Voltage PropagationSurge Voltage Propagation
copyrighted by IEEE
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Inductance L and capacitance C are expressed in
per unit length.
Stored energy in inductance is # LI 2
Stored energy in capacitance is # CE 2
Equating the two, we get
The wave propagation velocity is expressed as 1/$LC
It approximates speed of light [1000 ft/µs]
C
L
I
EZ ==0
Typical values of Z0: 200-400# for overhead Lines
20-50 # for insulated cables
Surge voltage propagation (Surge voltage propagation (concon’’dd))
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
10" 20" 40" 70"
E
1.33E 1.78E 2.27E 4.54E
Et
Voltage at the point of refraction = (E)(2Z2)/(Z2 + Z1)
Amplification PhenomenaAmplification Phenomena
A traveling surge-voltage, encountering in succession junctions with
higher surge impedance, may have its voltage magnitude elevated to a
value in excess of twice the magnitude of the initial voltage.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Standardized factory tests:
• 1 minute high potential [ hi-pot] test at power frequency
• 1.2/50 full-wave voltage impulse test
• For low voltage [<1000 V] equipment, additional wave shapes are
prescribed in IEEE std. C62.41.2-2002
Insulation Voltage WithstandInsulation Voltage Withstand
Insulation tests and ratings:
Standards have been developed that recognize the need for electrical
equipment to withstand a limited amount of temporary excess voltage
stresses above and beyond the normal operating voltages.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
IEEE C62.41.2-2002IEEE C62.41.2-2002
copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
100kHz Ring Wave (V & I)100kHz Ring Wave (V & I)
IEEE C62.41.2-2002IEEE C62.41.2-2002
copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
BIL
1.2!s
50!s
For tables: 6-1,2,3,& 4 in IEEE C62.41.2
Full-wave voltage impulse test waveFull-wave voltage impulse test waveBIL: Basic Impulse Insulation Level
copyrighted by IEEE
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Combination Wave for Short Combination Wave for Short Ckt Ckt II
copyrighted by IEEE
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Transformer Insulation Overvoltage TestsTransformer Insulation Overvoltage Tests
copyrighted by IEEE
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copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
copyrighted by IEEE
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
copyrighted by IEEE
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Harmonics in Distribution SystemHarmonics in Distribution System
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Harmonics in the systemHarmonics in the system
For system analysis purpose, the non-linear devices (e.g. power
electronics) can be generally treated as current sources of harmonics
The amount of harmonic voltage distortions depends upon Z v. f
characteristics as seen by the harmonic currents.
Higher the short circuit capacity of the system, lower the source
impedance of the system and, hence, lower the voltage distortions due
to harmonic currents.
Capacitor banks used for voltage control or reactive compensation can
be considered in parallel with the system when calculating the
commutating reactance, which would increase di/dt of commutation.
• Capacitance of insulated cables has similar effect.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
Normal flow of harmonic currents
Parallel Resonance conditions
L
Cresonance
X
X
MVAinsizebankcapacitor
MVAcircuitShortH ==
Capacitor bank resulting in series resonance
Higher FrequenciesHigher Frequencies Elicit ResonanceElicit Resonance
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
It is important to be able to analyze a system’s frequency response
characteristics in order to avoid having system resonance problems.
Harmonic currents flow from the non-linear load towards the point of
lowest impedance, usually the utility source.
System response characteristicsSystem response characteristics
Effects of harmonics can be grouped into three general categories
1. Effects on the power system – additional losses, radiated and
conducted noise, signature problems ( submarines)
2. Effects on the loads- motors/generators, transformers, power cables,
capacitors, electronic instrumentations, switchgear & relaying, static
power converters
3. Effects on communications [SCADA systems] – Telephone
Interference Factor [TIF] weighing –
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Cable Cable Derating Derating v. Harmonicv. Harmonic
for six-pulse converterfor six-pulse converter
copyrighted by IEEE
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VoltageVoltage Distortion Limits (Distortion Limits (!!69kV)69kV)
Industry Standards--IEEE Std. 519- 1992
copyrighted by IEEE
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Current DistortionCurrent Distortion Limits (120V - 69kV)Limits (120V - 69kV)
copyrighted by IEEE
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Case StudiesCase Studies
Case Studies Presented Interactively
1. One study included herein
2. Remaining study not included
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Objectives:
Compares two methods of transmitting power to isolated
load:
Method 1: Transmits the available single-phase power to a motor
drive inverter.
Method 2: Converts 3-Phase AC to DC and transmits it to the same
motor drive.
My-T Acres Farm Project, Batavia, NY -My-T Acres Farm Project, Batavia, NY -by Dr. Mohammed Safiuddinby Dr. Mohammed Safiuddin
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
500,000V !!!
120V
Transmission of 3-phase to isolated loads is expensive.
UNICO
Drive
Instead, Single-phase transmission would be more economical
BackgroundBackground
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1-Ph v. DC for VSD at point-of-load1-Ph v. DC for VSD at point-of-load
DC transmission
1-Phase AC transmission
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
System Efficiency W/W
0
10
20
30
40
50
60
1008 1107 1207 1308 1507 1607
Speed (RPM)
Eff
icie
nc
y (
%)
AC LINK
DC LINK
System Efficiency W/VA
0
0.1
0.2
0.3
0.4
0.5
0.6
1008 1107 1207 1308 1507 1607
Speed (RPM)
Ra
tio
(P
-ou
t/V
A-i
n)
AC LINK
DC LINK
ComparisonComparison
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System Current THD
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
1008 1107 1207 1308 1507 1607
Speed (RPM)
TH
D (
%)
AC LINK
DC LINK
System Performance - THDSystem Performance - THD
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
ConclusionsConclusions
Both DC and Single-phase AC transmission are more cost effective than
the 3-phase AC transmission for isolated loads ( Limited by the load
values).
DC power link offers several advantages over AC link:
• More efficient
• Allows lower components ratings
• Lower harmonic distortions on the grid supply.
• Better power factor
• Can be used to supply large loads.
APEC’10, Palm Springs, CA © 2010, D. C. [email protected]
End - Printed BookletEnd - Printed Booklet
Prof. Douglas C Hopkins, Ph.D.Dir. Electronic Power and Energy Research Laboratory
www.DCHopkins.Com
Prof. Mohammed Safiuddin, Ph.D.Research Professor
State University of New York at Buffalo
332 Bonner Hall
Buffalo, New York 14260-1900
+01-716-645-3115