井下电缆在线故障选线及定位方法研究

针对煤矿井下供电系统发生单相接地故障时故障点位置难以确定、现有离线测距方法测距精度低的问题,分析了井下电缆供电系统单相接地故障特征,提出了一种煤矿井下电缆在线故障选线及定位方法。该方法利用供电系统单相接地故障时暂态零序无功功率在选线频带内的极性选出故障线路,利用有些频带的暂态高频信号与故障距离成一定映射关系的特点,将不同条件下发生故障时得到的系统母线零序电压和线路零序电流作为输入样本对小波神经网络进行故障测距训练,从而实现故障定位。Simulink仿真结果验证了该方法的有效性和精确性。

Research of Method of On-line Fault Line Selection and Location of Underground Cable

In order to solve problems that it is hard to confirm fault position when single-phase grounding fault happens in underground power supply system and existing off-line distance measured methods are poor in precision,the paper analyzed characteristics of single-phase grounding fault of underground power supply system with cable and proposed a method of on-line fault line selection and location of underground cable.The method uses polarity of transient zero-sequence reactive power in frequency band of line selection to select fault line when single-phase grounding fault happens in power supply system,and takes zero-sequence voltage of system's bus and zero-sequence current of lines at faulting time as input samples to train wavelet neural network based on characteristics that transient signals with high frequency of some frequency bands map fault distance,so as to realize fault location.The Simulink simulation result verified validity and accuracy of the methods.