±800 kV直流输电工程受端换相失败对送端影响分析

Analysis of Influence of Phase Commutation Failure at Receiving End of DC Transmission Project on Feed End

以伊克昭—沂南±800 kV直流输电工程为研究对象,通过RTDS仿真系统模拟受端沂南站换相失败故障。分析认为:当发生换相失败时,逆变侧触发角增大,无功需求增大,交流电压降低;逆变侧换相失败的时间、长度、次数不同,对送端伊克昭站交流系统的影响程度也不一样;在直流系统大功率运行时,逆变侧换相失败对整流侧交流系统影响较大,小功率运行时对整流侧交流系统影响较小。建议换相失败时及时关注站内设备运行状态,检查阀外冷主泵、阀外冷风机、换流变冷却器、站用电系统运行工况。

Taking the±800 kV DC transmission line from Yikezhao to Yinan as a research object,the commutation failure in Yinan inverter station at the receiving end is simulated by RTDS simulation system.Analysis shows that when the commutation failure occurs,the trigger angle of the inverter side and the reactive power demand both increase,and the AC voltage decreases.The different time,length and times of inverter side commutation failure have different influence on the AC system of Yikezhao rectifier station.When the DC system is running at high power,the commutation failure on the inverter side has great influence on the AC system on the rectifier side.While when the DC system is running at low power,it has little influence on the AC system on the rectifier side.It is suggested that when the commutation fails,the operation status of the equipment in the station should be timely paid attention to,and the operating conditions of the main pump outside the valve,the air cooler outside the valve,the cooler of the converter substation and the power supply system of the station should be checked.