Method for detection of an earth fault loss in a three phase supply network involving differential measurement of current pulsing so that the system is linearized about an operation point

摘要

Method has the following steps: continual sampling and storage of measurement values of three conductor currents at a measurement point and determination of a zero current for each sample time point, continuous determination of the amplitude and phase of the currents using a DFT, FFT or similar method. Through the differential measurement of the pulsing the system is linearized about the actual operation point.