Research of wave-head characteristics of the fault-generated travelling wave on transmission line in different frequency bands

Wave-head characteristics of the fault-generated travelling wave on transmission line in different frequency bands are studied by using wavelet multi-resolution decomposition in this paper. Firstly, the travelling wave process on transmission line is analyzed and the fault-generated travelling wave is described by analytical expression. Then, the fault-generated travelling wave is decomposed into two parts: the irregular travelling wave component and the regular travelling wave component. It is verified by simulation that the wavelet modulus maxima of the fault-generated travelling wave and the irregular travelling wave are the same under low scales or high frequency bands. Finally, wave-head characteristics are obtained across scales by using the irregular travelling wave component instead of the fault-generated travelling wave on the premise of low wavelet scales or high frequency bands and wave-head steepness is considered. As the wavelet scale increases, the polarity of the wave-head keeps unchanged. Besides, the amplitude of the wave-head rises and approaches the value of the original wave-head amplitude, and the arrival time of the wave-head rises.