直流输电单极故障引发接地极线路击穿的定位方法研究

为实现直流输电单极故障引发接地极线路击穿故障点的快速准确定位,缩短供电恢复时间,提出一种基于换流站故障录波的接地极线路击穿点定位方法。通过理论分析,得到直流输电单极故障情况下换流站中性母线电压U_(DN)振荡频率随接地极线路等效电感的变化规律,结合接地极线路模型并考虑参数频变特性的影响,构建了基于"频率—电感—距离"三者关系的击穿点定位算法。利用西南至华东某特高压直流工程实际故障案例对方法进行了验证。结果表明:该方法的有效性和精度满足实用要求,且无需额外增加换流站软硬件配置,便于工程应用。

Research on location method of grounding electrode line fault caused by unipolar fault of HVDC transmission system

In order to realize the fast and accurate location of breakdown point of grounding electrode line caused by a HVDC unipolar fault, and shorten the power supply restoration time, a fault location method for grounding electrode line based on fault recorder of converter station is proposed. Theoretical analysis has revealed the relationship between the oscillation frequency of the neutral bus in the converter station UDN and the grounding electrode line inductance, combined with the line model and considering the effects of frequency dependent characteristics, a fault location algorithm based on the quantitative relationship between frequency, inductance and distance is proposed. Practical fault cases of a UHVDC project from Southwest to East China is used to check the method. The results show that the method is effective and accurate, and it does not need to increase the configuration of hardware and software of converter station, so it is convenient for engineering application. This work is supported by Youth Science Fund of National Natural Science Foundation of China (No. 51707019) and China Postdoctoral Science Foundation (No. 2016M592659).