FIELD: electric engineering. SUBSTANCE: faults starting signal generated by current protection of zero sequence of adjacent units is indicated as described starting signal enters much earlier than operation signal of voltage organ appears. Device has AND gate which has the first input connected with output of zero sequence current protection current organ of its own power unit through NOT gate. The second input of AND gate is connected with output of zero sequence voltage protection voltage organ. The third input is connected with outputs of current protection of zero sequence of adjacent power units of power station. The first input of the second AND gate is connected with outputs of current protection of zero sequence of adjacent units of power station. The second input of the second AND gate is connected with output of zero sequence voltage protection voltage organ though the second NOT gate. Output of AND gate is connected with the fourth input of the first AND gate through time delay organ, RS-flip-flop and the third NOT gate. Output of the first AND gate is connected with actuating unit through the first organ of time delay. Actuating unit turns power unit off. EFFECT: improved reliability of operation. 3 dwg
