Optimization for Postearthquake Resilient Power System Capacity Restoration Based on the Degree of Discreteness Method

The occurrence of a natural disaster such as a strong earthquake affects not only the capacity of a city's power supply system but also the normal operation of other lifeline systems. An urban emergency power supply system is used to manage the power supply restoration with the consumers divided into three types based on their impact and importance during a power failure. In this study, a power supply system equipped to meet the requirements of different restoration level facilities and enable the restoration of power after the occurrence of an earthquake was developed. A three-stage power restoration curve was formulated based on the postearthquake recovery process. The relative importance factors of consumers can be calculated with a normalization model based on membership degree. These relative importance factors were then combined with the postearthquake recovery capabilities of each consumer to calculate the overall recovery capability and equilibrium degree of the urban power system. Using the two foregoing indicators, the power supply recovery level of the power system after an earthquake was quantitatively analyzed, and the power supply scheme of the consumers with different power supply guarantee types was rationally optimized.