Analysis of key influencing factors and optimization strategy for safety boundary of converter station

In interconnected systems with increasing stability margin, power flow transfer may cause converter stations to operate outside the safety boundary, causing cascading failures of DC systems. In order to clarify key factors affecting safety boundary of converter station and propose effective and feasible optimization strategies. Firstly, based on PQ power domain, this paper analyzes constraints that affect safe operation of converter station, and determines safety boundary model of converter station composed of the intersection of multiple constraint power domains. Then the key influencing factors of safety boundary of converter station are analyzed, and optimization method of safety boundary to adjust AC system impedance is proposed by establishing the optimization interval of AC system impedance. Finally, the correctness of the theoretical analysis is verified by the simulation results based on the PSCAD/EMTDC software.