DEVICE FOR COMBINED ELECTRIC ENGINEERING PROCESS BASED ON PARALLEL CURRENT INVERTERS

摘要

FIELD: electricity. ^ SUBSTANCE: proposed invention relates to induction heating equipment and may be used for simultaneous metal melting and cup drying during reconstructive maintenance of induction-smelting furnaces. According to the invention the device includes three-phase three-coil low-frequency mains transformer, two three-phase diode bridge rectifiers, two filtering choke, two single-phase parallel current inverters with trigger units and two induction-smelting furnaces bypass connected by compensating condensers. Besides the primary coil of three-phase three-coil transformer is coupled with three-phase a.c. network and two secondary coils are connected with a.c. terminals of serial connected three-phase bridge rectifiers. Two single-phase serial-connected parallel current inverters are also connected to the above rectifiers through filtering chokes. The first induction-smelting furnace for metal smelting is coupled with output a.c. terminals of the first inverter. The novelty of the invention is the additional single-phase high-frequency transformer with the first coil being connected to the output a.c. terminals of the second parallel current inverter and the second coil being connected to the second induction-smelting furnace for cup drying. Metal is melted in the first induction smelting furnace when supply voltage from a.c. mains and control pulses to bridge rectifier valves and parallel inverters is supplied. Cup is dried out in the second induction-smelting furnace when no shortcuts to the ground are available and no additional equipment is present, which ensure the claimed technical result. ^ EFFECT: improvement of smelting equipment reliability and reduction of specific rated capacity. ^ 1 dwg