Fault Set Generation Method Based on Risk Assessment for Power Systems Under Unconventional Events

This study addresses the issue of overlooked disaster scenarios in large-scale regional simulations by proposing a post-earthquake coupled risk assessment method for power systems. An improved risk classification approach under seismic conditions is also developed, enabling a more comprehensive screening of fault sets. Specifically, the power grid is divided into multiple regions based on geographical location, and independent earthquake events are simulated within each region. Monte Carlo simulation is employed to generate initial fault sets that reflect seismic characteristics, from which the corresponding coupled risks are calculated. Based on the As Low As Reasonably Practicable principle, and incorporating both the Safety Accident Investigation Regulations of the State Grid Corporation of China and simulation results, a post-earthquake risk classification method is established. This provides practical guidance for power system operators to prepare effective emergency response plans in advance. Finally, the proposed method is validated using the IEEE 39-bus test system, demonstrating its effectiveness.