345kV SSVT Replacement Program

This project is being driven by violent failures at four critical ETT stations. The failures result in operational constraints and cause hot oil to erupt in a 40 foot radius and slow burning fires which can last for days. Failure teardown analysis of the units illustrates design and manufacturing flaws on both the high and low voltage windings of the transformers. The scope of this project is to replace all Alstom station service transformers with those from another vendor.

On February 1, 2021, ETT’s SSVT Replacement project was completed and placed in-service 11 months ahead of the original schedule due to the extraordinary efforts of the project team. To expedite work in light of safety concerns resulting from previous catastrophic failures, ERCOT agreed to allow nighttime outages during the ERCOT outage moratorium (May 15 – September 15), and crews were able to work more safely and efficiently by working 12-hour night shifts. Also, a steady improvement in field operations combined with prudent schedule management resulted in a reassessment and optimization of the schedule. In addition, there were no safety incidents recorded during the project.