Please provide a summary of your organization’s comments on the Planning Standards - Remedial Action Scheme (RAS) Guidelines Update straw proposal and September 26, 2022 stakeholder call discussion:
PG&E appreciates the opportunity to provide its perspectives on the straw proposal and looks forward to working with the CAISO and other stakeholders through the Planning Standards - Remedial Action Scheme (RAS) Guidelines Update.
In general, PG&E believes additional clarity in the proposal is necessary and that the RAS guidelines should attempt to keep RAS local to radial/semi-radial facilities and away from network flows which are difficult to predict.
PG&E also has the following question about the proposal and requests it be addressed in the revised straw proposal:
- Is generator auxiliary load/station service able to be tripped as part of a RAS?
If so, this could affect the generator tripping mechanism. Tripping locations could become important if auxiliary load/station service cannot be tripped. In general, PG&E recommends avoiding tripping auxiliary load/station service.
Please see below additional comments
Provide your organization’s comments on the proposed updates to the RAS guidelines, as described in section 3.2:
In the proposal for ISO G-RAS3, the CAISO recommends that “RAS should trip load and/or resources that have effectiveness factors greater than 10% on the constraints that need mitigation.” PG&E believes a 10% dfax is too low and should be between 25%-50% to include projects that are more effective.
In ISO G-RAS4 Section A, the CAISO proposes that “RAS should have no more than 6 contingencies”. PG&E believes 6 contingencies are too many given this proposal conflicts with monitoring less than 4 elements in ISO G-RAS4, Section B (see below).
In ISO G-RAS4 Section B, the CAISO recommends that “RAS should not be monitoring more than 4 elements.” PG&E requests the CAISO define what is an element. For example, outage detection could need to monitor up to four (4) circuit breakers for one branch outage. Would this count as one element or four elements?
In ISO G-RAS4 Section E, the CAISO proposes that “RAS should only monitor overloading facilities no more than 1 substation beyond the first point of interconnection.” PG&E supports the concept of proposing simple and local RAS. However, as it is written, it appears to focus more on interconnection projects and there could be conditions that a RAS would be necessary other than interconnection projects. Thus, PG&E recommends more general language be used.
In ISO G-RAS4 Section G, the CAISO proposal states “RAS should not include logics to…” PG&E recommends the verbiage be modified to “RAS should strive to not include…,” because there could be situations that necessitate its inclusion. PG&E also believes there is a typographical error in the second paragraph where it refers to “above RAS standard” since G-RAS4 is a guideline.
In ISO G-RAS6, the straw proposal quotes the guideline (originally ISO SPS3) and proposes to maintain it as a guideline due to retirement outlook for Diablo Canyon Power Plant (DCPP) remains fluid at this time. It is unclear what the P2 generation tripping limit is since P2 was not listed. PG&E requests the CAISO in the revised straw proposal include what the P2 tripping limit is.
If G-RAS7 is intended as a temporary “bridge” until system reinforcements are placed into service, then PG&E recommends language be included in the guideline to enforce the long-term plan. In other words, a temporary RAS is allowed for bridging when there is commitment for a long-term plan. There should be a time limit for temporary RAS.