When the S-transform is implemented to determine the fault line in distribution network by detecting the tens of kHz high frequency transient component of the fault traveling wave,the moment corresponding to the maximum component in the highest frequency row of the S-transform magnitude matrix of zero modal bus voltage is the real mutation moment of zero modal bus voltage.

Then considering the characteristic of power system traveling wave fault location and avoiding phase-moving when measuring the head of traveling wave using multi-scales wavelet transform,this kind of wavelet is used to assay the fault signal.

Study on the noise reduction of power line fault current traveling wave based on morphological wavelet;