Blackout anticipation test: investigation of induced voltage and resonant event causing sustained high voltage at isolated network

In case of an electrical blackout, an available power plant can be used to energize a nearby nuclear power plant via an isolated network. To validate and operationalize these power restoration networks, blackout anticipation tests are periodically conducted. During one such test, an induced voltage of 160 kV was recorded, along with a sustained high voltage exceeding the regulatory operating limits for the tested 400 kV power system. The grid topologies under test are rarely encountered during normal operation of power systems but they may occur during or after a blackout. Therefore, better understand the phenomenon leading to this damaging sustained high voltage is fundamental for safe and reliable power system restoration.