GROUND FAULT DETECTION METHOD, DEVICE, AND SYSTEM FOR ELECTRIC POWER SYSTEM

摘要

A ground fault detection method, device, and system for an electric power system. An electric power system comprises a plurality of branches and nodes thereof, and each branch is provided with a protection device. The detection method comprises the following steps: S1, respectively measuring differential currents of multiple nodes of the electric power system and voltages corresponding to the multiple nodes, the voltages being potentials from a positive electrode line or a negative electrode line to a protection line or potentials from the positive electrode line or the negative electrode line to the ground; and S2, on the basis of the differential currents of the multiple nodes and the corresponding voltages, respectively calculating average powers of the multiple nodes, and when the sum of the average powers of the multiple nodes exceeds a first threshold, determining that a ground fault has occurred within the range of the multiple nodes. According to the method, a ground fault in an electric power system can be accurately determined, and the location where the ground fault occurs can be positioned.