FIELD: electricity.
SUBSTANCE: invention relates to method for detecting ground fault in network further providing the possibility for determination whether the fault is located on the line side or on the load side from the detection point. The method for directional detection of ground fault in multi-phase power system, a device for implementing the method, an indicator of short-circuit current flow to the ground containing a device of directional detection of fault, a relay of ground protection containing an indicator of fault is provided. The method of directional detection of ground fault in multi-phase power system of medium voltage, in particular, with compensated neutral and/or insulated neutral, includes the following stages: detection of fault by voltage change (V0) zero sequence; determination of direction by phase difference, in particular, by angle or sign of product between derivative of zero sequence current (dI0/dt) and voltage of zero sequence (V0) under conditions of continuous fault.
EFFECT: reduction of interference effect, simplification of measurement procedure, simplification of calculation, in particular, when detecting at low sampling.
15 cl, 4 dwg
