Governor Droop Criteria BPA Comments May 10, 2011 webinar

BPA Key concern: governor response has a significant effect on SOL studies and reliability. Therefore, governors should be: In-service and responsive to frequency (follow droop characteristic) TOP/ RC/ BA need to know status and droop characteristic GOP has a responsibility to get governors back in-service as soon as practical; TOP/ RC/ BA need to know the timeline for restoring the equipment.

OC remanded Criteria to address How long the governor can be out of service Provide notice when the governor was out of service Applicability What we want to cover today: Review BPA comments and provide technical support Answer drafting team questions provided by Ken Wilson on May 5, 2011.

Comments we’ve provided V1 (Nov 2010) – BPA suggests criteria should include: Report governor setting to TOP Report governor status (on/off) to TOP Governors should be in-service. If forced out of service, GOP should provide workplan and timeline for corrective actions. Evidence of status and droop settings should also include performance data. V2 (Feb 2010) – BPA expressed concern that: Criteria allows governors to be out of service for an unrestricted amount of time GO/ GOP has no responsibility to notify appropriate operating entities of governor operating status

Question 1 In BPA’s proposed requirement WR2, what does the term “responsive to frequency” mean? A. This means nothing is blocking the natural governor response of the generator. Response should follow the set governor droop characteristic (3%-5%) in response to frequency deviations. Q. Would a unit that can only move one direction meet the intent? Would this language allow units to operate with valves wide open? We are not proposing that this criteria should mandate operating at less than its maximum generation. But if the generator has room to move in either direction in response to frequency, it should. How does BPA proposed to determine compliance with its proposal? A. Suggested wording: Upon request the Generator Owner/Operator shall provide data that shows the actual response of the generator to a specific event.

Question 2 The drafting team believes that the proposed requirement WR2 in PRC-001-WECC-CRT-1 – Governor Droop Setting Criterion is more restrictive than that proposed by BPA. This position is based on a requirement for any unit on line, regardless of the amount of time to have its governor in service except for certain reasons detailed in the standard, Please provide your reasoning for the allowances in your proposal that permits governors to be out of service for any reason. Please explain how BPA’s proposal is more restrictive than the proposed PRC-001-WECC-CRT-1 requirements. A. BPA would like to see a limit on the amount of time a governor can be out of service. For example under your proposal a governor could be out of service for repair for an infinite amount of time. The wording and time frames were only a suggest starting point and to reflect a requirement similar to the AVR and PSS requirements.

Question 3 Please explain why we should require an entity to have primary control governor action in service and responsive to frequency when there is not a requirement for a generator to have a governor. Isn’t the drafting team suggesting that the governor be in service? In other words, can Generator Operators indicate that they have removed the governor and therefore are not subject to the proposed requirement WR2 until such time as they desire to re-install a governor? If so, please explain how this language is better than what the drafting team has proposed. A. This is a good catch. BPA agree that this could be the case under BPA’s and the drafting teams requirement and should be addressed. BPA would like to see a requirement for a governor on all generator over XX MW level.

Question 4 Please explain why BPA’s proposed requirement R3 is not covered by the NERC Standards, including specifically TOP-003-1 requirement R2 and TOP-002-2 requirements R3 and R14. If BPA feels that the issue is not addressed by these requirements, please explain what is missing? TOP-003 R2 has no mention of governors. A. TOP-002 R3 has to do with planned output of the plants. TOP-002 R14 has to do with real and reactive output capability and AVR status. None of these standards deal with governors. QDT. Could the drafting team please explain why they think it is covered by these standard? Are any Generators reporting their governor status now?

Technical justification Reliability issue: Show how governor response modeling in studies affects SOL results. Therefore, Governors should be on BA/ TOP/ RC needs to know status References from WECC Modeling and Validation Governor Modeling Task Force