Single-phase-to-earth Fault Line Selection Method for Medium-voltage Distribution Network Based on Wavelet Packet Analysis
Qiufeng Xie, Yunhong Zheng · 2022
Using the dynamic simulation tool Simulink of MATLAB software, the single-phase-to-ground fault in the medium-voltage distribution network system is simulated. A method of judging fault time by wavelet transform of zero-sequence voltage is proposed, select a small amount of data before and after the fault time for wavelet packet decomposition, the characteristic frequency band is determined according to the maximum difference of wavelet packet decomposition coefficients. Obtain the wavelet packet coefficients of each output zero-sequence current and zero-sequence voltage in the characteristic band, and perform product processing on them, a new method for judging faulty lines according to the polarity of their products. A large number of simulation experiments show that the method has the characteristics of strong adaptability and feasibility, then improve the accuracy and effectiveness of subsequent fault detection and fault identification, it provides reference for the development of fault algorithm and detection equipment of medium voltage distribution network.