基于模式变换和小波变换的电力电缆故障测距方法

通过将小波变换与模式变换理论相结合,提出了一种电力电缆故障的在线测距方法,该方法采用暂态行波信号,首先将三相信号转换成模式分量,零模分量的小波变换系数用于判别故障的大致位置,然后利用线模分量的小波变换系数来确定行波到达时间.采用模式变换可避免传统行波方法中存在的受故障起始角影响的问题.仿真结果表明,该方法有很高的测距精度,是可行的.

A Fault Location Method Based on Modal Transform and Wavelet Transform in Underground Power Cable Lines

This paper puts forward a fault location method for power cables.In the proposed method,wavelet transform is combined with modal transform,and transient traveling-wave signal is used.After three phase signals are decomposed into their modal components,the wavelet transform coefficient of ground mode component can be used to identify the approximate position of the fault,and the wavelet transform coefficient of aerial mode component is used for identifying the arrival time of traveling-wave.Because the method utilizes modal transform,the problem of fault inception angle in almost all conventional methods can be avoided.The simulation results indicate that the proposed method has high accuracy in fault location,and the method is feasible.