FIELD: electrical engineering. SUBSTANCE: invention makes it possible to ensure continuous testing of serviceability of high-frequency channel of diphase protection of power line independent of value of load in it. Effect is achieved thanks to manipulation of transmitters under condition of control over voltage of substations with their connection in counterphase with compensation of voltage drop in power line. With starting of protection together with transfer from reduced parameters of transmitters to normal ones manipulation of transmitters is changed over from voltage to current in line on its both sides. Simultaneously change-over of operational condition of transmitter and its manipulation create conditions for testing of high-frequency channel independent of load in power line and for adherence to required selectivity of action. EFFECT: improved efficiency of relay protection. 3 dwg
