On Tuesday, March 28th, IEEE (PI)2 Austin hosted a Technical Meeting:  “ERCOT Odessa Grid Disturbance Events“ with speaker Julia Hariharan of ERCOT Independent System Operator (ISO).

  

Ms Hariharan discussed the progress in monitoring, analyzing and improving the operation of solar inverter based with respect to grid reliability. She focused on two major Inverter Based Resource (IBR) events that occurred on May 9th, 2021 and June 4th, 2022, originating in West Texas, which are  informally known as the “Odessa Events”.

These events resulted in the tripping of numerous inverter-based generators in West Texas on the ERCOT system. The scope of her discussion included:

·       Details concerning the origin and impact of each event

·       Causes of each solar PV reduction on the ERCOT system

·       Explanation of each inverter fault code

·       Corrective actions determined by discussions between ERCOT and inverter Original Equipment   Manufacturer (OEM)

·       Summary of ERCOT activities in response to Odessa Events

ERCOT collected data from the different solar resources affected by the events to determine the root cause. Some manufacturers were either out of business or on their way there. The overvoltage event and the underfrequency event were caused by improper measurement points causing incorrect overvoltage and overvoltage signals that tripped them off line unnecessarily. The circuit diagrams were reviewed and recommendations for design changes were implemented. The initiative indicated a collaborative solution, led by ERCOT, that improved the reliability and stability of the grid in the Odessa region. The speaker answered questions from the interested audience – a very successful meeting.
About the Speaker:
Julia Hariharan is an Operations Engineer in the Operations Analysis & Improvement group at ERCOT ISO, where she has been employed since 2021. Julia works alongside Patrick Gravois, a Lead Engineer on her team, to diagnose and analyze all issues related to severe IBR events, including the event that occurred in the Odessa area on June 4th, 2022. Her other responsibilities include documenting other NERC reportable events, assisting with Operations
Improvement meetings, analyzing data and providing information internally pertaining to significant grid events, and various other technical roles. Prior to joining the Operations Analysis & Improvement team, Julia completed the Engineer Development Program at ERCOT ISO, which is a self-paced rotational program for first-level engineers based out of the Network Modeling
group. She received her BSEE degree from the University of Akron in 2019 and her MSEE from Rensselaer Polytechnic Institute in 2020.