FIELD: electrical engineering. SUBSTANCE: proposed method depends on automatic correction of capacitive ground-fault current in 6-35 kV mains by adjusting inductance and current of arc-control reactor inserted in neutral line of power transformer in compliance with expected ground-fault current measured earlier. Method provides for multipurpose use of devices involved, high speed, and fine adjustment under all possible operating conditions of supply mains. To this end arc-control reactor is saturated by stabilized current of magnitude lower than that required for resonance tuning; variable-frequency oscillator is used as noncommercial frequency supply; expected capacitive single-phase ground-fault current is measured by scanning supply mains neutral with aid of variable-frequency oscillator through signal winding of arc-control reactor, finding resonant frequency of reactor inductance and present ground-fault capacitance of supply mains at noncommercial frequency, this being followed by calculation of expected capacitive single-phase ground-fault current through metal by finding square of ratio of supply frequency to found resonant frequency. EFFECT: enlarged functional capabilities. 1 cl, 1 dwg
