LC resonance mechanism analysis of fault transient for single phase earth fault in non-solidly earthed network

Transient principle is one of the main methods of single phase earth fault detection in non-solidly earthed network. Clear and detailed transient mechanism analysis can further improve the reliability of fault detection. According to impedance characteristics of transmission line, distribution line shown as distributed parameter model will alternate present capacitive and inductive with frequency increasing. Transient process of single phase earth fault is produced by series or parallel resonance between different modulus and different lines that present as capacitive and inductive respectively. Transient current produced by series resonance between line-mode and zero-mode network contains clear fault location information, but other resonance mechanisms of fault transient do not have this information. ATP simulation results prove the correctness of the resonance mechanism.