【摘要】 根据电缆–架空线混合输电线路上行波信号在连接点处发生突变的特点,提出了一种基于小波分析的电缆–架空线混合输电线路行波故障测距方法。向待测混合线路的电缆端注入脉冲电流,利用小波分析对注入的采样信号进行多分辨分析,得到模极大值点的位置。利用非故障相信号反射点的位置判别混合线路的连接点位置,再利用故障相与非故障相的差信号判别故障点,从而调用不同的算法实现混合线路的故障测距。采用ATP/Matlab的仿真结果表明,该方法可对混合线路上任意点的短路故障进行测距,也可对断线故障进行精确的测距。基于小波分析的方法可准确识别反射脉冲,减小电缆线路分支和近区故障反射波对测量精度的影响,测距精度高。更多还原

【Abstract】 According to the feature that traveling wave signal abruptly changes at the junction point of hybrid transmission line consisting of power cable and overhead line, a wavelet analysis based traveling wave fault location method for the hybrid transmission line is proposed. Injecting impulse current at the terminal of power cable into the hybrid transmission line to be detected and conducting multi-resolution analysis of injected sampling signal by wavelet analysis, the position of modular maximum point of sampling signal is obtained. The position of traveling wave’s reflection point in non-faulty phase is used to distinguish the position of junction point of the hybrid transmission line. The differential signal of the faulty phase and the non-faulty phase is employed to detect the faulted point. Thereby different algorithms can be called to implement fault location of hybrid transmission line. The results of simulation by ATP/Matlab show that the proposed method can be used to carry out fault location for short circuit fault occurred in any position of hybrid transmission line as well as accurate fault location for open phase failure. The method based on wavelet analysis can accurately identify reflected impulse, reduce the influence of line tap of cable line and reflected wave caused by near-by fault on measuring precision, the location precision is high.更多还原