Fault Current Mitigation Using 550kV Air Core Reactors

A short circuit study performed in March 2015 indicated that fault current levels at 525 kV Palo Verde and Hassayampa substations were approaching the interrupting capability (63 kA) of installed circuit breakers. A technical team was formed to study and develop short-term (for next two years) and long-term solutions to this problem. This paper discusses various options considered by the technical team for short-term and long-term mitigation. The design of the chosen technical solution is documented in detail. The applied electrical tests were discussed and contrasted with recommended tests according IEEE.