METHOD FOR IDENTIFICATION OF FEEDER WITH SINGLE-PHASE EARTH FAULT AND AUTOMATIC LOAD TRANSFER IN DISTRIBUTION NETWORKS Russian patent published in 2009 - IPC H02H3/16 G01R31/08 

FIELD: electricity.

SUBSTANCE: zero sequence currents without their own measurement and according selection of setpoints serve as monitored electric values, and only direction of supplying feeder current serves as basic parametre, which in its turn increases noise immunity. Continuous monitoring of zero sequence current condition in units, timely selective detection and disconnection of damaged point make it possible to avoid double earth faults. For practical realisation of suggested single-phase earth fault protection method, it is possible to use available devices and functional elements. Operations of measurement, multiplication with further integration, signal coding, information exchange with adjacent units, control of switches may be realised in a comparably simple manner with the help of microprocessor devices. It makes it possible at comparably low material expenses to provide for reliable, selective and fast-acting network protection against single-phased earth fault.

EFFECT: improved reliability of protected network operation.

3 dwg, 2 cl