Cascading failures, Resilience enhancement, Coordinated defense strategy, Restoration dispatch, Double-layer optimization, Production of electric energy or power. Powerplants. Central stations, TK1001-1841

Blackout events caused by cascading failures have induced enormous losses in power systems. Good defense strategies are helpful for stopping cascading failures spread, which not only reduces system losses, but also improves the system’s ability to cope with the cascading failures. However, the current studies mostly focus on single-stage defense strategy and lack coordination of preventive, emergency and restoration dispatch (CPERD) against cascading failures. This paper proposes a CPERD methodology to counteract cascading failures for resilience enhancement. We first analyze the propagation mechanism and the prediction method for the propagation paths of cascading failures. Second, we explore the necessity and feasibility of whole-process coordinated dispatch under cascading failures and design a CPERD model framework. Based on this framework, we further analyze the impact of whole-process coordinated dispatch on the propagation path of cascading failures. Third, preventive dispatch, emergency dispatch and restoration dispatch sub-models are separately modeled to minimize the dispatch cost. Since the model has the characteristics of multi-stage and multi-objective, a double-layer optimization framework and an improved particle swarm optimization algorithm are introduced to solve the CPERD problem. Finally, the IEEE 39-bus and IEEE 118-bus test systems are taken as examples for simulation analysis. The results show that whole-process coordinated dispatch can effectively reduce the final load loss and overall dispatch cost, and enhance power system resilience against cascading failures.