IDA Restoration- The Transmission Engineering Efforts

Hurricane IDA left huge impacts on the electric systems in Southern Louisiana. One of the major impacts of IDA is the destruction of 230kV Mississippi river-crossing line in between Avondale and Harahan which resulted in the radial configuration of transmission systems for Harahan, Kenner, and Destrehan area. Around 25k customers which includes several major industries were getting power through a single source 230kV line from Little Gypsy. In those circumstances, any outage of that single source line could cause blackout of 25k customers. To mitigate that reliability issue within a short time, transmission owner utility planned to build a short line to connect Destrehan-Harahan and Snakefarm-Labarre 230kV lines which resulted in a multi-terminal transmission line. The protection and relaying of the unconventional multi-terminal transmission line is a complex problem. This paper presents the protection challenges of the multi-terminal transmission line, the implemented solution, and its benefits.