高压直流输电系统输电电缆的故障定位方法

Fault Location Method of HVDC Transmission Cable

MMC-HVDC系统直流侧架空线路在单极故障发生时,单极线路各频段的电压占比因故障极线路的不同而出现不一样情况,所以提出基于模糊比值分析的MMC-HVDC系统单极接地故障定位方法。该方法通过S变换将故障时的各频段电压进行分离,凭借各频段电压占比不同,实现仅靠一侧装置对系统故障极快速定位,并用神经网络训练找出各个频段电压占比在整体测距中的权重,最终实现对故障位置的精确定位。最后利用PSCAD/EMTDC电磁暂态仿真软件搭建两端双极柔性直流输电模型,仿真结果验证了所提故障定位方法的准确性以及实用性。

When the single pole fault occurs in the DC side overhead line of system, the voltage proportion of each frequency band of the single pole line presents different situations due to the different fault pole lines. Therefore, a single pole grounding fault location method of MMC-HVDC system based on fuzzy ratio analysis is proposed in this paper. In this method, the voltage of each frequency band during fault is separated through S-transform. Depending on the different proportion of voltage of each frequency band, the fault pole of the system can be quickly located only by one side of the device, and the weight of the proportion of voltage of each frequency band in the overall ranging can be found by neural network training, so as to finally realize the accurate location of fault location. Finally, PSCAD/EMTDC electromagnetic transient simulation software is used to build the two terminal bipolar flexible DC transmission model. The simulation results verify the accuracy of the proposed identification method and ranging algorithm.