Rapid assessment of substation earthquake risk based on minimal cut sets

Electrical substation systems have been severely damaged in previous earthquakes. It is important to realize the rapid seismic risk assessment of substation systems before an earthquake occurs. This paper proposes a rapid seismic risk assessment framework based on seismic hazards and a functional network model. According to the structural connectivity of the substation, the series and parallel connections of equipment were clarified. Considering the power load capacity of equipment and the power transmission requirements of systems, a dualfunctional network model combining structure and electricity was built. On the premise of ensuring earthquake risk probability information, the hierarchical simulation of the fault tree model was carried out. Also, the minimum cut set algorithm was used to rapidly evaluate the seismic risk of the substation system. Aiming at reducing the risk of substation function failure, two risk reduction strategies of seismic retrofitting and additional redundant equipment were put forward. After the seismic analysis of a typical 220 kV substation, key equipment of the substation and the optimal risk reduction strategies were obtained.