NOTICE DATE: May 26, 2023

NOTICE TYPE: M-A052623-01 Operations

SHORT DESCRIPTION: Identified solar facilities need to consult with their OEM about DC voltage unbalance mitigation

INTENDED AUDIENCE: All Resource Entities owning solar facilities with Power Electronics inverters

DAYS AFFECTED: May 26, 2023 until completion

LONG DESCRIPTION: During the 2021 solar PV disturbances in California and the 2022 Odessa disturbance event in ERCOT, multiple solar facilities with Power Electronics inverters had inverters trip due to a DC Bus Unbalance fault code. Power Electronics has released a firmware upgrade that will reduce the tendency of inverters tripping due to this issue. The NERC 2022 Odessa Disturbance Report recommends "ERCOT should ensure that all facilities with inverters from this manufacturer have updated their firmware to mitigate these performance issues as quickly as possible."

ACTION REQUIRED: All identified Resource Entities owning solar facilities with Power Electronics inverters should consult with Power Electronics to verify if this firmware upgrade should be implemented to improve the ride-through capabilities of the facility. If the upgrade is needed, the Resource Entity should schedule a date for the firmware upgrade to be implemented. Affected Resource Entities should notify their ERCOT Account Manager with the plan and timeline for implementation by June 30, 2023.

ADDITIONAL INFORMATION: Facilities that have inverters trip during events in which voltage and frequency remain within the "No Trip Zones" of the voltage and frequency ride-through curves contained within Nodal Operating Guides Sections 2.6.2 and 2.9.1 will be reported for a ride-through failure violation. It is the responsibility of the Resource Entity to ensure their facilities can properly ride-through these system events.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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