Simulation and research of single-phase to ground of distribution network

Based on simulation and analysis of single-phase to ground system of distribution network, utilizing the good time-frequency characteristics and localized ability of wavelet packet to deal with transient information of fault in this paper. The method can accurately capture the voltage wave head of instantaneous fault to provide a theoretical basis for fault location of distribution network. Besides, when analyzed the waveforms of zero-mode voltage and current, it found that the fault line polarity of zero-mode voltage and zero-mode current are opposite but the polarity of health lines are same in the first cycle. In addition, the amplitude of fault line is larger than the health lines obviously. Utilized the finds above, the relay protection scheme of zero-mode power can be constructed, and the scheme is immune to the influence of fault time, transition resistors and other factors. Therefore, it provided a good condition for the development of relay protection level of distribution network.