刘海金,靳鹤志,王金浩,王亮,温伟杰,李斌.含高比例分布式电源的直流配电系统故障恢复过电压机理及其抑制[J].电测与仪表,2023,60(11):45-52. liuhaijin,jinhezhi,wangjinhao,wangliang,wenweijie,libin.Fault recovery overvoltage and its suppression in DC distribution system with high DG penetration[J].Electrical Measurement & Instrumentation,2023,60(11):45-52.
Fault recovery overvoltage and its suppression in DC distribution system with high DG penetration
Aiming at the overvoltage during fault recovery of DC distribution system, this paper studies overvoltage generation mechanism and puts forward an overvoltage suppression method based on current limiting inductance matching design. This paper first introduces the topology of typical DC distribution system and gives the current and voltage fault characteristics of two core converter equipment (VSC and DC/DC converter) under bipolar short-circuit fault. Based on the equivalent circuit of the normal system after fault isolation, the generation mechanism and influencing factors of fault recovery overvoltage are analyzed. It is found that the root cause of fault recovery overvoltage is the inconsistent voltage drop rate of each converter during the fault. Then, the matching design principle of the outlet current limiting of each converter is proposed to ensure the same voltage drop rate of the converter and the breaking capacity of the DC circuit breaker. The fault current limiting and fault recovery overvoltage are also taken into account. Finally, the simulation results of PSCAD/EMTDC show that the proposed method has good overvoltage suppression effect.