A location of a fault in an ungrounded power distribution system is determined by identifying a faulty feeder section and a type of the fault using voltages and currents measured before and after the fault and selecting the location of the fault at the faulty feeder section by testing a relationship of a current over a voltage measured at boundaries of the faulty feeder section after the fault with different equivalent admittance matrices of the faulty feeder section determined for different candidate locations of the fault of the determined type. The fault is a short-circuit fault including one or combination of a single-phase-to-ground fault, a phase-to-phase fault, a double-phase-to-ground fault, a three-phase-to-ground fault, and a phase-to-phase-to-phase fault.
