N-1安全网络约束下基于综合潮流熵的输电网关键线路辨识方法OA

Identifying critical transmission linesprone to triggering cascading failures is vitalto ensure the operational security of power system.Existing studies on critical lines overlook N-1 security network constraints and the bidirec-tional flow transfer effects between target and other lines.This paper proposes a method for identifying critical lines in transmission grid based on integrated flow entropy under N-1 security network constraints,improving accuracy of critical line identification and effectiveness of cascading failure defense.An entropy index with interval-weighted av-erage load rates is established,representing the impact of different N-1 contingencies on the load rates of target lines.A flow distribution entropy index is also built by weighting the interval-average load rate with probabilities of N-2 line outages,measuring the consequences of target line disconnections from load distribution balance.Hence,a comprehensive flow entropy index is constructed to identify critical linesprone to cascading failures more accurate-ly under N-1 security constraints.Based on the IEEE 39-bus system,comparative results show that the proposed method identifies critical lines more accurately.Expanding the critical lines can significantly reduce the risk of load loss due to cascading failures.