FIELD: electrical engineering. SUBSTANCE: voltage level across input terminals of three-phase supply mains is chosen to equal mean voltage across inductor terminals during top- and-bottom smelting process; in order to reduce its variation range during initial smelting period number of inductor working turns is reduced and active power injected in furnace inductor is increased; during next smelting period and up to its end number of working turns and amount of power injected in inductor are increased and decreased, and transformer-thyristor modules are used to maintain desired voltage level across inductor terminals, power factors, and load unbalance in the course of smelting; special vector monitoring system is used for transformer-thyristor modules. Proposed method and device provide for cutting down active material consumption by 50%, reducing power requirement by 30% per ton of smelted metal, and enhancing reliability by 30% due to dispensing with mechanical contact members in device. EFFECT: improved performance characteristics and environmental friendliness of smelting process. 3 cl, 8 dwg
