The invention discloses a three-phase controllable polar direct-
current electric arc furnace power supply device which comprises a main
transformer, a main loop and a control loop.
Secondary side windings of the main
transformer comprise a first winding and a second winding. The main loop comprises a first three-phase fully-controlled bridge
rectifier circuit, a third three-phase fully-controlled bridge
rectifier circuit, a fifth three-phase fully-controlled bridge
rectifier circuit, a second three-phase fully-controlled bridge rectifier circuit, a fourth three-phase fully-controlled bridge rectifier circuit and a sixth three-phase fully-controlled bridge rectifier circuit, wherein the first three-phase fully-controlled bridge rectifier circuit, the third three-phase fully-controlled bridge rectifier circuit and the fifth three-phase fully-controlled bridge rectifier circuit are connected with the first winding, and the second three-phase fully-controlled bridge rectifier circuit, the fourth three-phase fully-controlled bridge rectifier circuit and the sixth three-phase fully-controlled bridge rectifier circuit are connected with the second winding. The control loop comprises six current transformers, a trigger, a pulse distribution circuit, a pulse inhibition circuit, a synchronous
transformer and six pulse amplifying circuits. The three-phase controllable polar direct-
current electric arc furnace power supply device is simple in structure, convenient to use and operate and capable of accelerating the melting speed of a direct-
current electric arc furnace, reduces heat shut-down, improves heat efficiency, prolongs the service life of a furnace body of the direct-current
electric arc furnace, and is high in practicability and convenient to popularize and use.