A probabilistic method is presented for the detection and location of very high resistive, permanent single-phase earth faults in medium voltage, radial operated distribution networks (20 kV). The systems considered have an unearthed or a compensated neutral and the fault resistances covered are in the range 5–220 kΩ. The algorithms of the method are based on the change of the neutral-voltage and zero-sequence currents, measured at the MV substation and also at the distribution line locations. The feasibility of the method was verified by an analysis based on system data recorded during field tests in real power systems.
- earth faults
- probabilistic methods