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NERC Case Notes: Reliability Standard IRO-010-2

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NP19-12-000: Consolidated Edison Co of NY, Inc. (CEOCNY)

Region: NPCC

NERC Violation ID Standard Requirement VRF/VSL Discovery Method Start Date End Date
NPCC2018019020 IRO-010-2 R3 Medium/Lower Self-Report 10/9/2017 10/10/2017
NPCC2018019446 FAC-009-1 R1 Medium/Moderate Self-Report 6/18/2007 1/30/2018
NPCC2018020745 FAC-008-3 R6 Medium/Lower Self-Report 7/1/2016 11/9/2018

Issue: IRO-010-2

On January 23, 2018, Consolidated Edison Co. of NY, Inc. (CECONY) submitted a Self-Report stating that, as a Transmission Owner (TO), it was in violation of IRO-010-2 R3. CECONY did not use the mutually agreed format between itself and its Reliability Coordinator (NYISO) for data specifications related to NYISO's Real-Time monitoring.

The root cause of this violation was the failure of the CECONY substation working group to follow internal protocol to acquire approval from the System Operator before scheduled work began at a substation that affects equipment ratings.

FAC-009-1

On March 28, 2018, Consolidated Edison Co. of NY, Inc. (CECONY) submitted a Self-Report stating that, as a Transmission Owner (TO), it was in violation of FAC-008-3 R6. CECONY did not establish Facility Ratings consistent with its Facility Rating Methodology (FRM) for nine Facilities. NPCC later determined that the violation began under FAC-009-1 R1. Accordingly, NPCC determined that CECONY was in violation of FAC-009-1 R1 from June 18, 2007 until December 31, 2012 and then was in violation of FAC-008-3 R6 from January 1, 2013 until January 30, 2018. NPCC further determined that, for purposes of this violation, there was no substantive change in CECONY's compliance obligations under the two applicable Standard Requirements.
The root cause of this violation is inadequate oversight and controls over the coordination between the DFR software and the Energy Control Center (ECC) SCADA server. Prior to FAC-009-1 coming into effect in 2007, CECONY had a facility ratings methodology that followed the accepted utility practices of the time. After the effective date of FAC-009-1, CECONY's methodology for establishing feeder ratings included identifying the most limiting element. However, CECONY did not ensure that the pre-2007 Facility Ratings calculated by DFR software respected the MLE and that that correct ratings were displayed on the SCADA system to the System Operator.

FAC-008-3

On November 30, 2018, Consolidated Edison Co. of NY, Inc. (CECONY) submitted a Self-Report stating that, as a Transmission Owner (TO), it was in violation of FAC-008-3 R6. CECONY did not establish Facility Ratings consistent with its Facility Rating Methodology (FRM) for eight Facilities.

CECONY's FRM requires the use of the most-limiting element (MLE) as the Facility Rating for its Facilities. CECONY initially discovered this violation as part of the planning for a capital project to replace 138 kV disconnect switches when it discovered the thermal ratings of a 138 kV intra-substation feeder did not respect the most MLE of the Facility. CECONY performed an extent of condition review and discovered this violation affected eight (8) of its one hundred and fifty-one (151) BES transmission feeders that are non-DFR feeders. CECONY has a total of 175 BES transmission feeders with 24 of them being in the DFR system. In the case of these 8 feeders that represent 4.6% of CECONY's BES feeders, the Facility Rating did not respect the most limiting in-series piece of equipment or MLE. The noncompliant Facilities consisted of two 345 kV transmission feeders and six 138 kV transmission feeders, all of which are located within CECONY's New York City Transmission Load Area and all of which became BES elements on July 1, 2016.

This violation started on July 1, 2016, the date when all eight Facilities were identified as BES Elements under the revised Bulk Electric System definition and ended on November 9, 2018, when CECONY corrected the Facility Ratings to be consistent with its FRM for all eight feeders. In particular, CECONY corrected the ratings for the eight Facilities in its "Tie Feeder Rating Tabulation" (a.k.a the "book" rating) that is developed by Transmission Engineering and entered the correct ratings into its EMS/SCADA system.

The root cause of this violation is that CECONY's verification of the ratings of new BES transmission elements was not fully effective prior to providing the ratings to the System Operation Department.

Finding: IRO-010-2

This violation posed a minimal risk and did not pose a serious or substantial risk to the reliability of the bulk power system. The existence of incorrect ratings in the EMS could negatively impact the reliability of the BPS under stressed system conditions if the operating authority is unknowingly operating to a higher rating than the equipment can accommodate. In this case, however, pre-outage studies were performed by CECONY and the NYISO as part of the NYISO's scheduling and approval process. The scheduling process allows the opportunity for the CECONY or NYISO to study and possibly deny the outage request one week in advance and then an opportunity to study again and possibly deny the outages as the October 9, 2017 operational day was beginning. On October 9, 2017, the NYISO and/or CECONY System Operator would have cancelled the job before the scheduled 7:00 am start time had system conditions warranted such cancellation. At no time during the approximate 30-hour duration of the violation did the system configuration change to cause an increase in loading on either feeder that exceeded the 554 MW reduced ratings. No harm is known to have occurred.

FAC-009-1 and FAC-008-3

This violation posed a minimal risk and did not pose a serious or substantial risk to the reliability of the bulk power system.

The use of the inaccurate DFR ratings in the EMS could affect the reliability of the BPS under stressed real-time system conditions if the operating authority is unknowingly operating to a higher rating than the equipment can accommodate. Advance planning studies that involved these 24 feeders that have DFR was performed using the more conservative book ratings, not the dynamic rating.

However, the risk of this noncompliance was reduced by the following factors:

1) CECONY operates the transmission system on an N-2 basis secured to NORMAL ratings.

2) The violation consisted, largely, of the EMS showing an incorrect STE Rating to the Operator, which are rarely reached even after a contingency occurs.

3) The CECONY methodology for operating the power system keeps real time power system flows under the NORMAL rating under normal operating conditions and obligates the System Operator to return facilities back to under NORMAL ratings in response to any contingency as soon as possible. The methodology also does not allow for an STE contingency alarm that results from the Real Time Contingency Analysis program to remain; the System Operator must adjust the system immediately to clear the STE contingency alarm.

4) When real-time issues occur, the CECONY System Operator operates in a conservative fashion to prolong the life of BES elements. The System Operator must clear an Over Normal alarm within 3 hours instead of the Planning allowance of 24 hours. The System Operator must clear an Over LTE alarm within 15 minutes instead of the Planning allowance of 3 hours. The System Operator must clear an Over STE alarm within 5 minutes instead of the Planning allowance of 15 minutes.

5) Based on a review of historical data, there were no instances during the period of noncompliance where the nine feeders experienced real time flows that exceeded any of the corrected ratings level (Normal, LTE, STE) of the MLE.

No harm is known to have occurred.

Penalty: $50,000

FERC Order: Issued June 27, 2019