Research on Dynamic Fault Recovery Strategy of Distribution Network Based on Multi-objective Optimization Considering Fault Hazard Degree

In this paper, a dynamic fault recovery strategy considering fault hazard degree is proposed to solve the large-scale power outage caused by the line fault. This proposed approach organically combines fault hazard degree, power supply demand with optimization model of power supply recovery. Then an adaptive matching mechanism of fault recovery model is established based on fault hazard degree. Based on the topology structure formed by breadth-first search, the node depth coding technology (NDC) is introduced to accelerate the speed of topology analysis. For emergency fault recovery demand, a fast topology analysis method based on the node depth and virtual power and an "exit as soon as feasible" mechanism is defined to find the power supply recovery channel in the shortest time. Finally, an improved non-dominant sorting genetic algorithm (NSGA-II) based on loop coding was used to solve the model, and preserving initial node (PIN) and changing initial node (CIN) in NDC were adopted to replace the crossover and mutation in traditional algorithms, avoiding infeasible solutions during iteration. Case study of the simulated failures of IEEE 33 node system and comparison with the existing methods proves that the proposed strategy can reconcile the speed and performance of power supply recovery decision, and realize the efficient search of the power supply path.