基于FIMD和小波变换电缆双端行波测距新方法

New two-terminal cable traveling wave fault location method based on FIMD and wavelet transform

针对电力电缆故障定位误差较大问题,提出基于FIMD和小波变换模极大值导数双端行波测距新方法。利用PSCAD仿真软件建立电力电缆模型,变换各测量点电流突变量相模,分解变换后模分量FIMD。利用小波变换对分解所得IMF1分量求取模极大值导数,找出暂态信号奇异点。根据首个暂态行波奇异点,确定初始行波到达线路两端时间,计算故障距离。结果表明,该方法测定电缆故障距离精度高、具有应用可行性。

In view of the poor accuracy in present power cable fault location methods, a novel fault location method based on the principle of two-terminal traveling wave was applied to fault location for power cable, the fault location based on fast intrinsic mode decomposition and wavelet transform modulus maxima derivative. Firstly, PSCAD was applied to establish the simulation model of power cable, Phase-to-phase transformation of the measurement point current was carried out, the current component of the measuring point was decomposed by fast intrinsic mode decomposition（FIMD）. secondly, the wavelet transform was applied to extract the modulus maxima of the first intrinsic mode decomposition（IMF1） component, and the first derivative was obtained by the modulus maxima, found the singularity of the transient signal. finally, the time of the initial traveling wave arrived at the double-ended of the line, according to the first transient traveling wave, and calculated the fault distance. Result of PSCAD based on test show that the proposed method was of high location accuracy and feasibility.