By Holden Mann

FERC accepted settlements Friday with Public Service Company of New Mexico (PNM) and two utilities owned by Berkshire Hathaway Energy — Nevada Power (NEVP) and Sierra Pacific Power Co. (SPPC) — for violations of NERC reliability standards. The settlements with NEVP and SPPC carried penalties of $231,000 and $153,000, respectively; a penalty of $70,000 was assessed for the PNM settlements.

NERC submitted the settlements to the commission on Feb. 27, filing a spreadsheet Notice of Penalty for PNM’s violations (NP20-8) and separate NOPs for NEVP (NP20-9) and SPPC (NP20-10). In a notice Friday, FERC said it would not review the settlements, leaving NERC’s penalties intact.

Rating Revisions

Although SPPC and NEVP both operate under the NV Energy brand, the utilities were cited separately by the Western Electricity Coordinating Council for violations of reliability standard FAC-009, covering the establishment of facility ratings, and VAR-002, relating to the maintenance of generator voltage or reactive power schedules.

The FAC-009 violations were assessed following self-reports submitted by both entities on Dec. 14, 2016, after a joint internal technical assessment revealed that several of their facility ratings did not include all applicable facilities. In addition, the ratings did not include all required elements. Further investigation found that the violation began on June 18, 2007, when the standard went into effect. In particular:

• Eleven transmission lead lines — including one owned by SPPC, one owned by NEVP. and nine owned jointly — did not have established facility ratings.
• Wave traps and relay settings were not taken into consideration by SPPC when rating transmission lines of 200 kV and above, or by NEVP for any applicable facilities.
• Current transformers were not included in facility ratings by either utility, and relays were also not included by NEVP.
• Lead lines to certain substations did not have established facility ratings.
• Facility ratings were not established for series and shunt compensation devices.
• SPPC did not update facility ratings following changes to its system.
• NEVP had no facility ratings, or incorrect ratings, for 24 transmission lines when the facility ratings methodology changed from FAC-009 to FAC-008.

Overall, SPPC had 92 of its 210 facilities with incorrect or no established ratings, while NEVP had no or incorrect ratings for 76 of its 223 facilities.

WECC assessed the violations as posing a serious and substantial risk to reliability of the bulk power system because of the possibility of overloading a BPS element and causing neighboring facilities and protection systems not to operate as intended. Neither NEVP nor SPPC had effective preventive or detective controls that could have prevented this outcome.

In response, both entities implemented mitigation plans — identical except for minor differences in phrasing — that WECC verified as completed by June 20 in the case of SPPC and June 30 for NEVP. Elements of the plans include establishing peer-checked facility ratings for solely and jointly owned facilities consistent with facility ratings methodology; creating a facility rating change control process; and creating an internal task force to ensure that facility ratings follow reliability standards in the future.

Repeated Voltage Deviations

NEVP and SPPC’s VAR-002 violations stemmed from a joint quarterly compliance review conducted on Oct. 26, 2017, with each entity submitting a self-report on July 22, 2018.

During the review, SPPC found that between April 10 and Sept. 13, 2017, one of its generation facilities deviated from the transmission owner’s generator voltage schedule eight times, with a maximum deviation of 1.15% for six hours. In addition, between June 25, 2017, and Aug. 17, 2018, another facility deviated from the voltage schedule 22 times; the maximum deviation was 0.96% for more than 22 days.

WECC identified the root cause of SPPC’s violation as “a lack of clear instructions, training or guidelines” for meeting the established voltage schedule. SPPC also lacked preventive controls, which WECC considered a systemic issue because it revealed a “lack of consistency in SPPC’s approach to meeting the voltage schedule.”

In response, the utility implemented mitigation measures that included revisions to its internal generation procedure; in-house training focused on taking and tracking voltage measurements; and creating additional warning systems for deviations in voltage. WECC verified the measures were completed on March 28, 2019.

NEVP discovered 659 deviations from the voltage schedule at one of its facilities between Dec. 7, 2016, and Nov. 29, 2017, with a maximum deviation of 2.27% for 10 minutes. Further investigation revealed two additional facilities that deviated from the schedule: One deviated eight times between Dec. 7, 2016, and March 14, 2017, and the other five times between March 15 and Sept. 1, 2017.

The utility attributed the deviations to “incorrect methods employed by plant personnel to take voltage readings.” Mitigating steps, completed on Jan. 16, 2019, included revising internal generation procedure for maintaining network voltage schedules; rescinding internal policies that conflicted with the voltage schedules; and expanding reporting requirements at the affected facilities.

In assessing the utilities’ penalties, WECC credited both NEVP and SPPC for self-reporting the violations, cooperating throughout the process and accepting responsibility. However, the regional entity also noted that both companies’ internal compliance programs failed to detect or address the issues. In addition, the FAC-009 violation was particularly lengthy, lasting nearly 10 years. NERC’s Board of Trustees Compliance Committee agreed that the monetary penalties in both cases were “appropriate for the violations and circumstances at issue.”

PNM Files SOL, Maintenance Issues

PNM’s penalties concerned violations of reliability standards TOP-002 and TOP-004 — concerning operations planning and transmission operations — as well as PRC-005, relating to transmission and generation protection system maintenance and testing.

The violations of TOP-002 and TOP-004 concern the same event on Sept. 12, 2016, when a circuit breaker in one of the utility’s 345-kV switching stations faulted internally. Although the breaker was in two separate zones of protection, one did not operate because of a previously undetected malfunction; as a result, the fault was not fully addressed, and several transmission lines and generation units tripped offline.

The TOP-002 violation began when PNM’s system operators failed to update the system operating limit (SOL) after the fault was cleared, having assumed that this would be done automatically by the energy management system; instead, the limit was not changed until the following day. The TOP-004 violation arose from the failure to restore system operations within 30 minutes. Both violations were self-reported to WECC on Feb. 6, 2017.

WECC determined that PNM had “failed to maintain accurate computer models utilized for analyzing and planning system operations,” but that the utility had quickly invoked contingency reserves, started all available load-side generation and requested emergency assistance. PNM did not operate above SOLs at any time during the event. The RE also credited PNM for not only mitigating the specific issues that arose during the incident, but for taking “above and beyond” actions and investments in the years since to proactively reduce risk in its system.

PNM’s violations of PRC-005 stem from two incidents of failure to document maintenance on its facilities. In the first case, the utility reported on Oct. 26, 2016, that it lacked full maintenance records on four batteries, two transmission relays, eight battery chargers and 155 instrument transformers. The second instance was reported on May 25, 2018, and involved maintenance and testing records for two microprocessor relays and one electromechanical relay at a substation.

The root cause of the violations was determined to be ambiguous instructions for documenting and retaining evidence in the first incident, and “a lack of internal controls to ensure accuracy” in the second. WECC noted that the utility was following a stricter timeline for its protection system devices than is required by the standard. In addition, the relays involved in the second violation were considered secondary protection and their failure would likely not result in a significant loss of load in the BPS.

To mitigate the violations, PNM has ensured maintenance on the relevant hardware is completed and has corrected any inaccurate records. It has also established regular meetings to discuss maintenance issues on relays and monthly compliance reviews on all protection system devices subject to PRC-005.