VDCOL控制作用在换相失败下的影响研究

Study on the Influence of VDCOL Control on Commutation Failure

摘要: 换相失败是常规高压直流输电(LCC-HVDC)的常见故障，发生换相失败时，若不能及时得到有效控制，则会危及直流输电系统的正常运行。在控制系统中，低压限流控制(VDCOL)能防止连续换相失败的发生。本文首先介绍了换相失败的定义、原理以及危害，然后分析了国际大电网会议(CIGRE)的Benchmark模型中整流侧和逆变侧的控制原理，分析Benchmark模型中VDCOL的参数改变对交直流系统的影响，并设置三相接地故障引发系统换相失败，改变VDCOL的参数进行仿真来验证VDCOL的参数改变对交直流系统的影响。

Abstract: Commutation failure is a common fault of conventional high voltage direct current. If commutation failure cannot be effectively controlled in time, it will endanger the normal operation of HVDC system. In the control system, Voltage Dependent Current limiter (VDCOL) can prevent the occurrence of continuous commutation failure. This paper first introduces the definition, principle and harm of commutation failure, then analyzes the control principle of rectifier side and inverter side in the Benchmark model of CIGRE, analyzes the influence of parameter change of VDCOL in the benchmark model on AC/DC system, and sets three-phase grounding fault to cause system commutation failure, changes the parameters of VDCOL for simulation to verify the parameter change of VDCOL Influence on AC/DC system.