NERC Case Notes: Reliability Standard IRO-005-3.1a


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NP20-6-000: Bonneville Power Administration

Reliability Standard: TOP-002-2.1b; TOP-004-2; TOP-007-0; IRO-005-3.1(a); IRO-010-1a

Requirement: TOP-002-2.1b: R1, R4; TOP-004-2: R1; TOP-007-0: R1; IRO-005-3.1(a): R9; IRO-010-1a: R3; IRO-005-3.1a: R9; IRO-0101a: R3

Violation ID: WECC2017017579, WECC2017017591, WECC2017017588, WECC2017017589, WECC2017017584, WECC2017017585

Method of Discovery: Self-Report

Violation Risk Factor: Medium (TOP-002-2.1b, IRO-010-1a); High (TOP-007-0); Lower (IRO-005-3.1a)

Violation Severity Level: High (TOP-002-2.1b R1); Severe (IRO-010-1a, IRO-005-3.1a, TOP-007-0); Moderate (TOP -002-2.1b R4)

Region: WECC

Issue: On May 18, 2017, BPA submitted a Self-Report stating, as a Transmission Operator (TOP), it had a potential noncompliance with TOP-002-2.1b R1. On November 30, 2016, BPA was implementing an outage as a part of the boundary Remedial Action Scheme (RAS), which entailed line loss logic for three separate lines. BPA did not correctly implement the published Study Limit Information Memo (SLIM), as is required by BPA's Operating Plan during the outage. The Dispatcher, implemented a restricted generation limit of 650 MW at the boundary generation station, rather than at the flowgate as specified. BPA did not lower the boundary SOL from 1300 MW to 650 MW. This mistake resulted in BPA operating a boundary SOL that was 650 MW higher than the setting should have been. As a result, the boundary RAS was operated in a degraded state. In addition, BPA had not included the boundary RAS in the list of Special Protection Systems that were incorporated into the Coordinated Outage System and therefore not reported to BPA's RC.

The outage work that resulted in the boundary RAS is usually completed one line at a time. When the SLIM was issued in this case, the Dispatcher also reviewed a Dispatch Standing Order (DSO) but the guidance was not applicable, which resulted in BPA not manually entering the SOL into the control system and causing the alarm monitoring to not alert to three SOL exceedances between 2:15 PM and 2:45 PM on November 30, 2016. Due to the lack of alarms, the Dispatcher did not realize there were SOL exceedances.

Finding: WECC determined these violations in aggregate posed a moderate risk and did not pose a serious and substantial risk to the reliability of the BPS. In this case, BPA was already operating its system with the RAS in a degraded state. If BPA were to have lost another line, the RAS could have caused a loss of load and potentially opened the remaining lines entirely. Further, BPA implemented weak preventative controls but effective monitoring controls as this issue was discovered during a routine monitoring activity nine days after the issue occurred, on December 9, 2016. As compensation, instead of setting the correct SOL, BPA instructed the main generation station for these lines to limit its generation to 650 MW. This action by BPA reduced the risk because instead of changing the SOL to address its mistake, it instructed the main generation station to limit its generation which then lowered the flows on the path without changing the SOL.

Penalty: $0

Duration of Violation: About 7 ½ hours on November 30, 2016

FERC Order: Issued December 30, 2019 (no further review)

Midcontinent Independent System Operator, Inc. (MISO), FERC Docket No. NP15-14-000 (December 30, 2014)

Reliability Standard: IRO-005-3.1a

Requirement: R1

Violation Risk Factor: High

Violation Severity Level: Lower

Region: ReliabilityFirst

Issue: MISO self-certified that some of its facilities experienced a diminished ability to determine post contingency voltage and thermal conditions for six hours on January 30, 2013. Due to sequencing issues in MISO's remedial action scheme, a shift engineer implemented a corrupt contingency case file into the Energy Management System resulting in the real-time contingency database to operate with 2,626 less contingencies. Personnel were unable to identify the alarm for the incorrect number of contingencies because several additional alarms were ringing at the same time. However personnel became aware of and corrected the issue when several 69 kV lines experienced new post contingency overloads due to a trip in a transmission line.

Finding: ReliabilityFirst determined that the violation posed a moderate risk to the BPS reliability as MISO was not monitoring its RC effectively. However, MISO continued to perform real-time monitoring and there were no IROLs associated with the violations. While SOLs were exceeded they did not result in any post-contingency stability or voltage issues and there was no evidence of pre-contingent thermal, stability or voltage issues. In addition, four projected post-contingent SOLs did not exceed the BES parameters. MISO neither admitted nor denied the violations. In approving the settlement agreement, the NERC BOTCC found that issues related to MISO's Network Model were only associated with the monitoring of post-contingent element conditions and did not hinder MISO's ability to perform other monitoring functions. Moreover, the issues were not related, affected a small percentage of the facilities MISO monitors and were indicative of other technologies that depend on large amounts of data. This was MISO's first violation of the standard and none of the violations posed a serious or substantial threat to BPS reliability. While MISO self-reported the violations, they were delayed. But MISO did have an internal compliance program in place, which ReliabilityFirst considered a mitigating factor. MISO was cooperative throughout the duration of the violation and there was no evidence that it attempted to conceal the violations.

Penalty: $0 (aggregate for 4 violations)

FERC Order: Pending

NP20-1-000: Peak Reliability (PEAK)

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NP18-10-000: Electric Reliability Council of Texas, Inc. (ERCOT)

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