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Remedial Action Schemes Reliability Subcommittee. Vahid Madani Chair Pacific Gas and Electric, Co. WECC PCC/OC/MIC Meeting June 2004. Outline. NERC Definition Application and Implementation Design development Process Standards and Compliance Schemes Reviewed by Subcommittee
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Remedial Action Schemes Reliability Subcommittee Vahid Madani Chair Pacific Gas and Electric, Co. WECC PCC/OC/MIC Meeting June 2004
Outline • NERC Definition • Application and Implementation • Design development Process • Standards and Compliance • Schemes Reviewed by Subcommittee • Subcommittee Function, Membership, and Benchmarking Efforts • Wide Area Monitoring and Challenges Ahead • Questions ??
Special Protection System (SPS) • NERC Defines SPS: • Automatic protection system (also known as a remedial action scheme) designed to detect abnormal or predetermined system conditions • Take corrective actions other than and/or in addition to the isolation of faulted components to maintain system reliability. • Actions may include changes in demand, generation (MW and Mvar), • System configuration to maintain system stability, acceptable voltage, or power flows. • Not included: • (a) Underfrequency or undervoltage load shedding • Fault conditions that must be isolated • Out-of-step relaying (not designed as an integral part of an SPS). www.NERC.com
Planning, Application, and Implementation • Increased Transfers • Added Reactive Support • Utilizing Reactive Supports Elsewhere in the Region • Cascading Outages • RAS Failure would result in: • Bulk transmission system performance outside the limits of the WECC performance requirements. • Impact to the Interchanges, transfers capabilities • Impact to contractual agreements in terms of flows and reactive margins
Development ProcessSpecial Protection Scheme (SPS) • Definition and Need • Development Process • Design and Analysis Tools • Commissioning • Functional Results • Periodic Automated Maintenance • Operator Training • Smart Restoration Tools
Design and Implementation Standards • Establish and Document Regional Review Process For Special Protection System (SPS) installations • Section III F (S1): • An SPS shall be designed so that cascading transmission outages or system instability do not occur for failure of a single component of an SPS which would result in failure of the SPS to operate when required • Section III F (S2): • Incorrect operation or unintended operation of an SPS when considered by itself and not in combination with any other system contingency shall meet the system performance requirements as defined under categories A, B, and C of Table I of the I.A. Standards on Transmission Systems
Compliance Requirements • Requirement to demonstrate that a failure of a single component of an SPS, which would result in failure of the SPS to operate when required, would not result in cascading transmission outages or system instability • For worst operating condition • Requirements that misoperation, incorrect operation, or unintended operation of an SPS, when considered by itself, shall meet the system performance requirements of Standard I.A. categories A, B, and C of Table I • Requirements for periodic review and Regional re-certification of the process document and database
Planning Standards (Section III) • Redundancy • Similar to Protection and Control Standards • Designed to allow equipment maintenance • Designed so that cascading transmission outages or system instability do not occur for failure of a single system a SPS component which would result in failure of the SPS to operate when required • The need for redundancy in SPS should be based on an evaluation of the system consequences for the failure of the SPS to operate and the need to maintain overall system reliability • To meet the system performance requirements of NERC standard I.A. • Standards on Transmission Systems and associated Table I
Which RAS should be reviewed? • WECC Reliability Criteria: • RAS required to be reviewed by RASRS are those schemes for which failure would result in bulk transmission system performance in a neighboring utility outside the limits of the WECC performance requirements • RAS for which failure may result in unacceptable bulk transmission system performance within the scheme owner’s system may be reviewed at the request of the owner of the scheme or as deemed necessary by other Regional technical committees
Subcommittee Function • Principal function: • Promote the reliability of remedial action schemes within the WECC region by providing multidisciplinary overview • Reviews, make technical recommendations, and approves proposals for implementation • With potential widespread cascading outages • Includes contingency N-1, N-1-1, N-2 type conditions • Focuses attention on major RAS within the WECC • Work is coordinated and draws on the information developed by other WG • Other PC and OC Subcommittee and Working Groups when necessary
Membership • Comprised of industry qualified members familiar with various aspects of RAS • Many are knowledgeable representatives with remedial action schemes within the region • Industry Participation Such as IEEE, IEC, CIGRE • Provides for reasonable geographic representation • Includes expertise in a variety of application and design disciplines (Engineering and Specialists) • Communication and Network systems • Information Systems • Control and Automation systems • Transmission planning • Operations engineering • Protective relaying systems engineering • Substation design
Some Industry Activities • CIGRE TF38.02.24 Defense Plans Against Extreme Contingencies • Design and Deployment of a Well Coordinated Overall Defense Plan • WECC RAS Reliability TF - Design and Implementation Standards and Review Criteria • CIGRE TF38.02.19 System Protection Schemes in Power Network • IEEE Power Systems, System Protection SC • Report on “Wide Area Protection and Emergency Control” (WG C-6) Special Protection Schemes, Survey on Implemented Scheme • IEEE Power Systems, System Protection SC • Survey of Power System Protection Schemes (WG C-4)
Benchmarking Exercises • Review of the Guide For Design of Critical Communication Circuits and Reliability Measures – Prepared by the WECC Telecommunication WG • FCC considerations for wider applications of 6GHz band - Update on Telecommunication WG • Requirements For a Well Planned and Implemented Scheme IEEE and CIGRE Efforts • Understanding of the European and NE outage US and Canada Outage • Review of NERC Recommendations and RASRS Actions
Sample of Schemes ReviewedApril 2003- April 2004 • IPC, Hells Canyon Runback Scheme • PNM, Import Contingency Load Shedding Scheme (ICLSS) • PG&E / SCE Path 26 • SCE, High Desert Power Project (HDPP) • SCE, Pastoria Generation • BPA, Lower Snake RAS Presentation • SRP, PV-COI Mitigation RAS - Phase 1
Challenges Ahead • Cyber Security • Standardization of min. requirements • Performance / Throughput timing may be affected • Unobstructed Visibility • Telemetry (Flow, Voltage, Watts, Reactive voltage) • Frequency • Voltage • Phase angles and differentials • Use of multi-function devices for combined protection and SPS / RAS functions • Centralized vs. Distributed Systems • Smart Restoration
Use of a device such as a relay shared for both protection and RAS functionality simultaneously • Different functional requirements and device set points • Different maintenance, testing and operating needs • Potential complications and confusion from operating and maintenance prospective when both RAS and protection using the same device • Different maintenance intervals and maintenance priority levels - Based on intended application and levels of redundancy • Availability of the devices for routine system testing (Isolation or unavailability of the wide area monitoring devices may not cause system limitations while may not be acceptable from the equipment protection prospective) • Communication network, interfaces, and routing are different between WAPC devices and those used for conventional equipment protection
Pat Wood, III - Chairman, Federal Energy Regulatory CommissionBefore the Committee on Governmental AffairsUnited States SenateNovember 20, 2003 • We need to invest in: • Hardware and software that let operators manage the grid more effectively • Tools that improve system monitoring, evaluation, visibility, visualization and information sharing about grid conditions over a wide region …..
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