贵广二回高压直流输电系统换相失败的仿真分析

Commutation Failure Simulation and Analysis of Guizhou-Guangdong Ⅱ HVDC Transmission System

换相失败是HVDC系统最常见的故障之一。通过分析换流器换相失败的机理,归纳了HVDC换相失败的各种影响因素。以2008年南方电网数据为基础,基于PSCAD/EMTDC建立了贵广二回直流输电系统的详细模型,并分析了一次系统和控制系统的具体结构。对该直流输电系统逆变侧换流母线发生三相接地短路和单相接地短路故障的情况进行了仿真实验,研究了换相失败的判据及故障对系统的影响。仿真结果表明,虽然贵广二回直流输电系统发生换相失败,但由于该系统的高度可控性,当故障切除后,系统很快从换相失败中恢复。

Commutation failure is one of the most common faults in HVDC transmission system. The influencing factors of HVDC commutation failure are concluded based on the analysis of the mechanism of commutation failure. According to the data of Southern China Power Grid in the year of 2008, a detailed Guizhou-Guangdong Ⅱ HVDC transmission system is established using PSCAD/EMTDC, and the structures of primary system and control system are analyzed. The three-phase and single-phase grouding faults of inverter commutation bus are simulated. The criteria and effect on the system of commutation failure are studied. Simulation results show that, commutation failure occures in Guizhou- Guangdong Ⅱ HVDC transmission system, but due to the high controllability of the HVDC system, it restores from commutation failure quickly after the fault is cleared.