Permanent fault identification for distribution network based on characteristic frequency signal injection using power electronic technology

In order to identify the fault nature when phase-to-phase short circuit occurs in distribution lines and realize adaptive reclosing of more accurately, a identification scheme using an inverter-based power electronic technology supply from stored energy capacitor is proposed this paper. The corresponding device designed which composed rectification, storage inverters. Supplied by high voltage side transformers, three-phase symmetrical characteristic frequency signals are injected into de-energized network. Then type can be determined according positive sequence resistance equivalent network under different properties. paper, overall structure diagram system proposed, operation analyzed. control strategy maintain stability output voltage. feasibility rationality verified theoretical analysis simulation results.