Presentation on theme: "Gene Henneberg RAS Criterion Drafting Team Chair WECC Reliability Subcommittee’s RAS Criterion Concerns 4/28/2011 San Diego, California."— Presentation transcript:
Gene Henneberg RAS Criterion Drafting Team Chair WECC Reliability Subcommittee’s RAS Criterion Concerns 4/28/2011 San Diego, California
2 The Reliability Subcommittee requests that the OC allow the RS to review the criterion before approval by the WECC Board. The RS wants to insure that the application of TPL Standards and WECC TPL Criterion are being applied appropriately and that the RS understands clearly the definitions used in the criterion as applied to the definition of the RAS, WAPS and LAPS. RS RAS Criterion Review
3 The RS is unclear about the definition of a RAS,.... RAS Definitions Confusion (1) RAS (aka SPS) is defined in the NERC Glossary. The WECC-0055 drafting team and the proposed RAS Criterion adopted NERC’s definition without changes. WECC has not previously had its own definition, but actual practice was not entirely consistent with the NERC definition.
4... WAPS and LAPS and how the failure of what or not qualifies one or not. RAS Definitions Confusion (2) WAPS and LAPS are types of RAS. The Criterion defines them only to help WECC, the RASRS, and owners provide an efficient review process. Performance requirements are the same: No single point of failure System performance for an inadvertent operation Coordination with other protection, control and emergency procedures
5 RAS Definitions Confusion (3) The primary functional difference between LAPS and WAPS is the scale of the system impact if the scheme fails to operate. WAPS failure may result in Any NERC event Category, 1-5 The event may require a EOP-004 or DOE OE-417 report—larger events perhaps also a NERC report LAPS failure may result in NERC Category 1 or 2 event only Event may require EOP-004 or DOE OE-417 report— usually no separate NERC report
6 Since all RAS schemes are designed to be able to meet the TPL standards, failure of a RAS will result in TPL Standard violation and thus all RAS schemes would meet the definition of WAPS (Wide Area Protection Scheme) which requires much more detailed review and redundancy, needs better definition or clarification? Old use of “local” didn’t require TPL compliance. RAS meet TPL Standards (1)
7... all RAS would meet the definition of WAPS which requires much more detailed review... RAS meet TPL Standards (2) Not all RAS meet the definition of WAPS. NERC TPL Standards are not directly used to classify RAS as LAPS or WAPS. WAPS and LAPS need to meet the same TPL and PRC standards. Both require redundancy. Only the WECC review level changes. WAPS get detailed, full reviews while LAPS reviews primarily confirm the owner’s classification of the scheme as LAPS.
8 The intent of the criteria was to qualify as WAPS only if the impact did not meet the WECC Table W-1 criteria which is meant for neighboring system and not meant for internal system? WECC Table W-1 Criteria Failure of a RAS that resulted in failure to meet the “neighboring system” criteria of WRS1, WRS2 and Table W-1 would classify a scheme as WAPS. Compliance with the “neighboring system” criteria for a RAS failure would define a LAPS.
9 The RS believes the criterion is not clear regarding the applicability of the TPL standards in determining whether the RAS is required to meet the more strict requirement (no single point of failure) and the WECC Reliability Subcommittee should review the criterion before approval this criteria is approved by the WECC Board of Directors. Meet the “no single point of failure” requirement
10 No Single Point of Failure LAPS and WAPS are types of RAS. Both types must meet the TPL-001, TPL-002 and TPL-003 performance, “no single component failure”, inadvertent operation, and coordination requirements identified in PRC-012_R1.3, R1.4, and R1.5.... determine whether the RAS is required to meet the more strict requirement (no single point of failure)...
11 WECC RS RAS Criterion Review I think we are doing such a review now. Of course, the RS is free to provide any feedback it deems appropriate to the Board.... the WECC Reliability Subcommittee should review the criterion before approval by the WECC Board of Directors
12 WRS Application The TPL WRS criteria are listed as applying to external systems; however, WRS3 applies to internal systems (MVAR margin criteria). Is this what the Draft Team and OC intended? This was not intended, but should not be an issue WRS1 and 2 are tied to Table W-1 and are tied to impacts on external systems, so a RAS that violates WRS1 or WRS2 is a WAPS. Without impacts to external systems a RAS is a LAPS WRS3 also applies to internal systems, so a RAS that violates WRS3 is a WAPS.
14 RAS Criterion linked to other Criteria This proposed criteria's failure test is linked to WECC criteria. A SAR is now being developed to link the differences in the WECC TPL criteria and the proposed TPL Standards. When the WECC TPL Criteria change how will the changes be reflected in this proposed Criteria?
15 RAS Criterion linked to other Criteria Modifications to existing criteria will always have an impact on WECC Planning and/or Operations. If the proposed modifications may affect application of other criteria an evaluation of that impact will be necessary. Modified TPL-(001-004)-WECC-1-CR could affect application of this PRC-(012-014)-WECC-CRT-1. Exact impact can’t be known without the modified wording.
16 The previous WECC RAS review process mostly ignored local RAS The old WECC Way RASLocal RAS No single point of failureNo design requirements specified RASRS Review Required RASRS review not generally required
17 The new WECC RAS review process will review identify and local schemes to meet the NERC requirements The NERC Requirements WAPSLAPS No single point of failure RAS Review Required (full design review) RASRS review required (review classification)