The NOPR notes that one reason for the widespread outages associated with the August 14, 2003, blackout was the unnecessary operation of a number of backup distance and phase relays under non-fault conditions (i.e., under overload rather than true fault conditions). Thus, the NOPR seeks to establish standards that would either prevent or minimize the scope of future blackouts by limiting the operation of such protective equipment.
Thus, Reliability Standard PRC-023-1 requires certain transmission owners, generator owners, and distribution providers to set certain protective relays according to specific criteria to ensure that they detect only faults for which they must operate and do not operate unnecessarily during non-fault load conditions. NERC proposes that PRC-023-1 apply to load-responsive phase protection systems as described in Attachment A to PRC-023-1 with respect to: (1) facilities, the low side of which are operated or connected at 200 kV and above; and (2) facilities, the low side of which are operated or connected between 100 kV and 200 kV that are designated by planning coordinators as critical to the reliability of the bulk electric system. The Commission proposed to direct the ERO to modify PRC-023-1 to make it applicable to all facilities operated at or above 100 kV, but to consider "exceptions on a case-by-case basis for facilities operated between 100 kV to 200 kV that demonstrably would not result in cascading outages, instability, uncontrolled separation, violation of facility ratings, or interruption of firm transmission service."
The Commission also sought comments on a number of other issues:
- With regard to generator step up and auxiliary transformer loadability, the whether the ERO should modify the proposed Reliability Standard to address such facilities, or whether generator step-up and auxiliary transformer loadability should be addressed in a separate Reliability Standard, as the ERO intends;
- If the ERO separately addresses these facilities, what is a reasonable timeframe for the ERO to provide a Reliability Standard;
- Whether the ERO should develop a maximum allowable reach for zone 3/zone 2 relays and if so, whether the ERO should develop a modification to PRC-023-1 or a new Reliability Standard;
- Whether the ERO should develop a Reliability Standard or a modification that requires applicable entities to use protective relay systems that can differentiate between faults and stable power swings and phases out protective relay systems that cannot meet this requirement;
- Whether Requirement R1.2 should apply to Reliability Standard TOP-004-1 or whether a new requirement is needed so that transmission owners, generation owners, and distribution providers give their transmission operators a list of transmission facilities that implement Requirement R1.2;
- the Commission proposes to direct the ERO to submit a modification that requires any entity that implements Requirement R1.10 to verify that the limiting piece of equipment is capable of sustaining the anticipated overload current for the longest clearing time associated with the fault from the facility owner;
Effective Date
- For Requirements R1 and R2, NERC proposes that transmission lines operated at 200 kV and above and transformers with low-voltage terminals connected at 200 kV and above (except switch-on-to fault-schemes) be made effective on the beginning of the first calendar quarter following applicable regulatory approvals. The Commission proposes to approve this aspect of the standard.
- In light of the Commission’s proposal to direct the ERO to modify PRC-023-1 to make it applicable to all facilities operated at or above 100 kV, with the possibility of case-by-case exceptions, and to all facilities operated below 100 kV that are designated by the Regional Entity as critical to the reliability of the bulk electric system, the Commission proposes an effective date of 18 months following applicable regulatory approvals for facilities operated below 200 kV. The Commission seeks comment on these proposals.
Violation Risk Factor
- The Commission proposes to direct the ERO to assign a high violation risk factor to each of the sub-Requirements R1.1 through R1.13. The Commission seeks comment on this proposal.
- In light of the Commission’s proposal to direct the ERO to modify Requirement R3 and its sub-requirements, the Commission proposes to direct the ERO to assign a violation risk factor to the revised Requirement R3 and its revised sub-requirements that is consistent with the revisions and the Violation Risk Factor Guidelines.
Violation Security Levels
- Accordingly, the Commission proposes to direct the ERO to revise violation severity levels assigned to Requirements R1 and R2 as well as, to submit violation severity levels for sub-Requirements R1.1 through R1.13 that are consistent with the guidelines set forth in the Violation Severity Order as discussed below.
