A microcomputer-based unique digital fault diagnosis scheme of radial transformer feeders

This investigation aims to develop a comprehensive microcomputer based fault protection scheme for indicating various types of faults in a radial transformer feeder in subtransmission or distribution circuits and its protection against those faults. The type of fault in the feeder can also be determined by observing the phase angles of the primary currents of the transformer with which the feeder is connected at its secondary. This method dispenses off conventional electromagnetic relays and HRC fuses in feeder protection schemes. The developed system provides necessary information regarding the faulted phase and displays appropriate symbols on the display screen of the microcomputer about the type of fault.