Adatpive single phase fault identification and selection technique for maintaining continued operaton of distributed generation

This paper presents the development of an adaptive rule based fault identification and phase selection technique to be used in the implementation of single phase auto-reclosing (SPAR) in power distribution network with distributed generators (DGs). The proposed method uses only the three line currents measured at the relay point. The waveform pattern of phase angle and symmetrical components of the three line currents during transient period of fault condition are analyzed using conditioning rules with IF-THEN in order to determine the type of single phase to ground fault and initiate single pole auto-reclosing command or three phase reclosing command for other type of faults. The proposed method is implemented and verified in PSCAD/EMTDC power system software. The test results show that the proposed method can correctly detects the faulty phase within one cycle in power distribution network with DGs under various network operating conditions.