针对行波法在混合线路中波速不连续和波速选取经验值导致测距精度误差较大的问题.提出用测试分布电流的皮尔逊相关性,确定故障区间,采用变分模态分解法(variational mode decomposition,VMD)对信号分解,用Teager能量算子(Teager energy operator,TEO)找到能量突变点计算故障距离.通过PSCAD/EMTDC与MATLAB进行仿真.结果表明:测距精度有明显提高且不受过渡电阻和故障类型的影响.
Fault Ranging for Hybrid Transmission Line with Distributed Current Detection
In view of the great discontinuity of wave speed in the hybrid line and the large error of ranging accuracy due to the selection of empirical value of wave speed by the travelling wave method,the Pearson correlation of distributed current is tested first-ly to determine the fault interval,and the signal is decomposed by using the variational mode decomposition(VMD)method to find the energy mutation point to calculate the fault distance by using the Teager energy operator(TEO)to find the energy mutation point to calculate the fault distance.The simulation is carried out by PSCAD/EMTDC with MATLAB.The results show that the distance measurement accuracy is significantly improved and is not affected by transition resistance and fault type.