摘要
直流近区交流线路发生短路故障时,会引发换流站发生换相失败,形成交流系统故障和直流系统换相失败故障叠加而成的复故障,与传统交流线路短路故障表现出的特性有较大差异。首先给出直流换流站的工作原理,分析交流系统短路故障引发换流站发生换相失败期间的换流桥通路,从换流站晶闸管导通关断的角度给出复故障期间直流近区交流线路保护安装处测得的短路电流的变化情况、短路电流极大值与短路故障发生时刻的关系,给出单相短路故障期间直流近区交流线路换流站侧可以达到短路电流极大值的变化规律,并给出短路电流工程计算用的算式。仿真结果证实该算式的有效性,为混联电网短路电流计算提供参考。
Short circuit fault occurred in AC transmission line near HVDC converter station will cause commutation failure. The characteristics of multi-fault formed from superposition of faults in the AC system and DC system commutation failure are quite different from traditional AC line short-circuit fault characteristics. Firstly, the operating principle of a DC converter station is given and the converter bridge circuit under the circumstance of converter station＇s commutation failure caused by short fault in the AC system is analyzed. Then, based on the converter thyristors＇ state, the changes of short-circuit currents of AC transmission line near converter station during the multi-fault and the relationship between short circuit current maximum value and fault initial time are given, and the condition of short-circuit current in the DC side near converter station achieving maximum value during the single-phase short circuit fault is proposed. Finally, the formula applied in short circuit current engineering calculation is given. The simulation results confirm the validity of the formula, which provides reference for hybrid power grid short-circuit current calculation.
出处
《智能电网》
2016年第10期1007-1011,共5页
Smart Grid
基金
国家科技支撑计划项目(2013BAA02B01)~~
关键词
交直流混联电网
短路故障
短路电流计算
换相失败
AC-DC hybrid power grid
short-circuit fault
short circuit calculation
commutation failure
