Differentiation of faults from power swings and detection of high impedance faults by distance relays

For maintaining security and reliable operation of distance relays power swing blocking is necessary to prevent maloperation during power swings and high impedance faults detection is necessary for operation of distance relays, since distance relays may treat high impedance faults as load since the fault will be out of reach of the relay. This paper proposes an algorithm for differentiation of faults from power swing and high impedance fault detection by distance relay simultaneously by a single algorithm, based on extracting current waveform components using Prony method. The merit of this method is demonstrated by simulating different high impedance faults and also during power swing conditions using the ATP version of the EMTP.