Ground Fault Identification in Distribution Network Based on MMC Injection Detection Signal Strategy

Abstract

In order to improve the identification efficiency and accuracy of distribution network ground fault identification methods, this paper proposes a distribution network ground fault identification method based on MMC injection detection signal strategy. Extract the fault information of distribution network grounding line, calculate the current component of three-phase current, and obtain the grounding fault data of distribution network.The detection current of distribution network is obtained by injection signal detection strategy. The fault information matrix is formed by using the detection current information, and the time-frequency characteristics of MMC injection detection signal strategy are obtained according to the actual situation.The wavelet transform is used to remove the clutter in the fault feature vector, and the normalized processing is used to obtain and process the ground fault vector.According to the wavelet function, the characteristics of the distribution network ground fault signal are determined. Cassie model and Mayr model are used to obtain the final distribution network ground fault identification model to realize the distribution network ground fault identification.The experimental results show that the accuracy of the method can reach 96.1%, and the time of fault identification is only 25s. The above results show that the method can effectively improve the effectiveness of distribution network ground fault identification.