DEVICE FOR PROTECTION AGAINST GROUND FAULT IN NETWORK WITH COMPENSATED NEUTRAL Russian patent published in 2013 - IPC H02H3/16 

FIELD: electricity.

SUBSTANCE: device comprises a source of control current of 25 Hz, filters of zero sequence current, installed on each network line, and selective actuators connected to filters of zero sequence current, besides, the source of control current 25 Hz is connected via serially connected capacitor and throttle to an open delta of the 1st transformer of zero sequence voltage or to secondary windings of a single-phase voltage transformer or a group of several single-phase voltage transformers, high-voltage windings of which are connected between a neutral point of the network and earth, besides, secondary windings of voltage transformers may be connected both in series and in parallel, and each selective actuator connects a working channel, the inlet of which is connected to a filter of zero sequence current, and a brake channel, the inlet of which is connected to an open delta of the 2nd transformer of zero sequence voltage, besides, outlets of working and brake channels are connected to inlets of a summator, an outlet of which is connected to an output element.

EFFECT: provision of control current application via secondary windings of a voltage transformer and selective operation of a protection in case of alternating arc ground faults.

3 cl, 5 dwg