Single Phase to Ground Fault Line Selection in Distribution Network Based on Signal Injection and Variational Mode Decomposition

Resonant neutral grounding operation is the most common operation mode of large capacity distribution network. A fault line selection method based on the combination of variational mode decomposition and signal injection is proposed to solve the problem of single-phase grounding fault line selection in distribution network with resonant grounding operation. After a single-phase fault occurs in the distribution network, the signal is injected by the injection signal source through the neutral point. The signals of each outgoing line are sampled for the variational mode decomposition. Intrinsic mode functions are obtained and the energy values are calculated. The relative entropy of energy, which can reflect the subtle difference of signals, is used as the criterion for line selection. The results of simulation show that the method has a high accuracy.