摘要
换相失败是高压直流输电HVDC系统最常见的故障之一。换相失败期间,直流电压降低,直流电流增大,直流系统中断功率传输,换流站附近发电机的出力也随之改变,给轴系扭振造成冲击。单次换相失败和连续换相失败会使轴系疲劳损耗累积,缩短轴系寿命,给电网带来安全隐患。采用电磁暂态仿真软件PSCAD/EMTDC,建立了含发电机的,并且有详细质量块模型的直流输电系统,分析比较不同原因引起换相失败对轴系的冲击影响。结果表明由触发脉冲不可靠引发的换相失败与交流故障引发换相失败对轴系扭振影响相当,甚至造成的应力大于交流故障,因此对触发脉冲内部故障应引起足够的重视。
The commutation failure is one of the most common faults in HVDC systems. During a commutation failure, the DC voltage is reduced, the DC current increases, and the power transmission of HVDC links might be consequently blocked, then output of the generators near the converter station also changes, thus it have an impact on the shaft torsional vibration. Single or continuous commutation failure may cause accumulated fatigue loss and may shorten the expectancy life of the shaft, which has a security risk to the grid. In this paper, electromagnetic transient simulation software PSCAD/EMTDC is used to establish a HVDC system with a generator and detailed mass model which analyzes and compares the impacts on the shaft of different causes of commutation failure. The results show that the commutation failure caused by an unreliable trigger pulse and the commutation failure caused by an AC fault have similar impacts on shaft torsional vibration, and the former even has a greater impact than the communication failure caused by an AC fault. Therefore the internal fault of trigger pulse should be taken seriously.
作者
孙吉波
黄国栋
林建熙
SUN Jibo;HUANG Guodong;LIN Jianxi(Electric Power Dispatching Control Center of GPDC,Guangzhou 510600,China)
出处
《云南电力技术》
2018年第3期32-36,共5页
Yunnan Electric Power
