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Remedial Action Schemes Application and Implementation Requirements & Performance Assessment Measures. Vahid Madani Pacific Gas and Electric Co. Chair - Remedial Action Scheme Reliability Task Force (RASRTF) Presented at The PCC/OC/WMIC Joint Meeting October 25, 2001 San Diego, CA.
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Remedial Action Schemes Application and Implementation Requirements&Performance Assessment Measures Vahid Madani Pacific Gas and Electric Co. Chair - Remedial Action Scheme Reliability Task Force (RASRTF) Presented at The PCC/OC/WMIC Joint Meeting October 25, 2001 San Diego, CA
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 WSCC performance requirements.
Special Protection Systems Design and Implementation Process • Need For Clarifications Identified by NERC • Application (Safety Net and Operating Transmission Capacity) • For Consistency and Clarity • NERC (IDWG) has assigned a small team to the task of developing the necessary Standards to facilitate assessments • NERC Planning Standards includes a set of guidelines • IDWG has requested guidance from both the CRWG and the PSS regarding the procedure for making the needed changes • North American Electric Reliability Council (NERC) Committees and Work Groups: • CRWG - Compliance Review Working Group • PSS - Planning Standards Subcommittee • IDWG - Interconnection Dynamics Work Group
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
Design and Implementation Standards (cont’d)Compliance Requirements and Measurements • M1. Each Region whose members use or are planning to use SPSs shall have a documented Regional review process for SPSs to ensure that they comply with Regional criteria and guides and the NERC Planning Standards. • The review process shall include an SPS database that addresses the design, operation, functional testing of SPSs • The coordination of the SPSs with other protection and control systems. • Documentation shall be provided to NERC on request
Compliance Requirements (cont’d) • 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
Compliance Requirements (cont’d) • Requirements for monitoring, notification, and analysis of all SPS operations (Standard III F., S1-S2, M5) - TOS • The Regional review process shall be provided to NERC on request • Time frame: Five business days • Documentation necessary to conduct the process - RASRTF • Planning and Operation Review process - TSS and TOS • Other SPS Standards and Compliance Measurements, For example: • Design & Operational Review of New & Modified SPS (S1-S2) • NERC Measurement M3
NERC Planning Standards (Section III) Purpose of SPS • To protect against possible cascading outages • The goal of implementation of SPS is • To ensure that the system will retain full functionality during the worst operating conditions for which the SPS was designed • When protecting the system from damage, these protection systems should be designed to remove the least amount of equipment from the transmission network • The SPS should not erroneously operate • To cause outages of higher impact than originally designed for • An SPS operation should not negatively impact transmission system operation
NERC Planning Standards (Section III) • Redundancy • Similar to Protection and Control Standards • Designed to allow equipment maintenance • 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 • 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 the I.A. • Standards on Transmission Systems and associated Table I
Compliance Requirements • The Regions shall have, on file, a comprehensive process document for reviewing and ensuring that SPSs comply with Regional criteria and guides and the NERC Planning Standards • Described in Standard III F. S1-S2 and associated Measurement M1 • The process document should include details such as: • Requirement for an SPS database that includes detail on: a) Design b) Operation c) Functional testing d) Coordination with other protection and control systems
Within the WSSC • The SPS is referred as: • Remedial Action Scheme (RAS) • Several Committees Assist With System Reliability • Two Committees Work on RAS • RAS Work Group (WG) - part of the TOS • Works closely with the Relay WG • RAS Reliability Task Force (RASRTF) – Part of the JGC • Works closely with many technical committees
WSCC RASRTF SCOPE STATEMENT • Undertakes specific assignments from the Joint Guidance Committee (JGC) to: • Review existing and planned remedial action schemes for the purpose of promoting inter-utility coordination • Accomplish reliability expectations of existing and planned remedial action schemes • Promote consistency and to ensure that the application and design of RAS systems are dependable and secure
WSCC RASRTF HISTORY • Established in February 1985 by the JGC • Initially assigned the responsibility for reviewing RAS associated with the Pacific AC Intertie (PACI) • Subsequently, TF has received broader role as an oversight group for all new and upgraded remedial action schemes of significance • TOS and the relay work group (RWG) are responsible for routine and operational events • The TF chair is appointed by the JGC Chairperson • Term is 2 years with possible reappointment
RASRTF Function • The principal function of the Task Force is to promote the reliability of remedial action schemes within the WSCC region by providing a multidisciplinary overview function • For new and upgraded systems • As requested by technical committees • The Task Force also deals with special technical problems regarding remedial action schemes which fall outside the scope of other Subcommittees and Work Groups
RASRTF Functions • Establish a documented review process • Facilitate functional review of new or modified RAS • Present recommendations and findings to the JGC • Maintain liaison with other WSCC groups as required to promote reliability • Remain abreast of "state-of-the-art" practices to improve reliability of RAS • Review the historical reliability of the present remedial action schemes within WSCC as requested by the JGC • Undertakes other assignments from the JGC which require a group having a multidisciplinary background
Task Force Membership • Is comprised of industry qualified members familiar with various aspects of RAS • Many are knowledgeable representatives with remedial action schemes within the region • 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
Which RAS should be reviewed? WSCC Reliability Criteria: • Remedial Action Schemes that are required to be reviewed by the RASRTF are those schemes for which failure would result in bulk transmission system performance in a neighboring utility outside the limits of the WSCC performance requirements • Remedial action schemes 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
Which Schemes Should be Reviewed? • Before the scheme is initially put into service • How to handle Emergency situations? • Before significant modifications or extensions are made to the RAS • If the RAS modification involves new system planning studies • When new input or output locations are to be added • When a major component or system architecture change is required • If a RAS owner is not sure whether a change is significant • Report to the JGC and RASRTF for a decision • In the event of scheme failure (certain types)
Emergency Conditions • Seasonal studies determine the need for scheme installation • Changes in the Regional requirements • Double contingencies • Immediate need to meet certain operating limits deemed necessary by the JGC and technical study groups
What are Significant Modifications? Modification Requiring RASRTF Review: • Involves system planning studies • Input or output locations are added • Major component or system is upgraded • Architecture change occurs • When a utility is not sure if a change is significant, they should report to the JGC and RASRTF and let these organizations decide.
Process For Documenting Minor Modifications • Documented through the Annual WSCC RMS program and the RAS Catalog • Any problems identified should be communicated to the JGC and in turn to the RASRTF • May need to address emergency RAS addition or modification where there is not enough time to review the RAS
Scheme Failures Requiring RASTF Review • In addition to the RMS Reporting Process • For RASRTF, these are any accidental or unintended RAS operation that do not meet expected performance levels, or when a RAS failure or false operation causes voltage collapse or cascading • WSCC Reliability Criteria section 7.0 • If RAS failure occurs, the failure is considered credible until the owners of the facilities have demonstrated that the cause of the failure has been corrected and it is no longer credible
Five Year Review • Every five years, the review will consist of receipt of confirmation from the RAS owner of no significant modifications or failures of the scheme. • The design of existing schemes shall not be subject to further review if there have not been significant modifications or failures.
RAS Review and Approval Procedure • Send a draft copy of the RAS proposal with all applicable documentation to the TF Chair • Submission must be timely to allow proper evaluation • Recommend min. of 3-4 months prior to planned operation • Or 2-3 months prior to the next scheduled RASRTF • Recommendations may require additional studies, hardware, or scheme enhancements • The TF members will evaluate and determine the scheme complexity and the need for a presentation discussion
Information Required to Assess the Reliability of a RAS • “Procedure to Submit a RAS for Assessment by the Task Force” • Contains several sections • RAS scheme purpose and overview • RAS Design • Logic • Hardware (substation, transfer trip, auxiliary tripping, etc.) • Redundancy • Arming • Detection • Coordination with other protection and control schemes • Telecommunication channels and path routing • Actions Initiated
Information Required to Assess the Reliability of a RAS (Cont’d) • Monitoring • Commissioning, Maintenance, and Testing • Performance and operational history • RAS Operating procedure for abnormal contingencies • Does the RAS owner have operating procedures to address: • Partial loss of input data required for arming • Total of loss of input data required for arming • RAS Catalog Information