特高压直流输电系统逆变站换相失败对整流站的影响及其保护配置策略优化建议

Influence of Commutation Failure of Inverter Station on Rectifier Station in UHVDC Transmission System and Suggestions for Optimization of Its Protection Configuration Strategy

换相失败是特高压直流输电系统最常见的动态故障之一。以宾(宜宾)—金(金华)特高压直流发生的任一桥换相失败造成的异常扰动为例,理论分析其成因,详述换相失败后整流侧交流系统频率、电压、无功的暂态特性,进而研究对400 V负荷(主泵软启动器、外冷风机、换流变压器冷却器)的后续影响;并试着剖析了区域电网间多回特高压直流系统同时换相失败对同一送端电网系统稳定的影响。最后结合CFPREV(换相失败预测)逻辑模块分析了宜宾站换相失败保护策略,并提出合理的优化建议。

Commutation failure is one of the most common dynamic faults in ultra - high voltage direct current （ UHVDC ） transmission system. Taking the abnormal disturbance caused by commutation failure on any bridge of Bin （Yibin） -Jin （Jinhua） UHVDC transmission system for example, the reasons are analyzed in theory, and the transient characteristics of frequency, voltage and reactive power of AC system in rectifier side after commutation failure are described in detail. Furthermore, the subsequent impact on 400 V load （ soft starter for main pump, air cooling machine, cooler of converter transformer） is studied. And the influence of simultaneous commutation failure in multi - circuit UHVDC transmission system interconnecting regional power grids on the stability of the same power supply system is explored. Finally, combined with the logic module of CFPREV （ commutation failure prediction）, the protection policy for commutation failure of Yibin station is analyzed and the reasonable optimization suggestions are proposed.