Patent ID: 6421366
Filing Date: 2002-07-16
Classification: F27B,H02J,H02M,H05B,Y02P

Abstract:
Process for supplying current to an electric-arc melting unit for melting and heating metal, which unit is operated with at least two electrodes, characterized by the following steps:(a) the electric current from mains to a three-phase a.c. source is divided over at least two parallel power supply modules; (b) in each power supply module, the current is introduced as direct current via an uncontrolled three-phase bridge; (c) then the current is stored temporarily in individual direct-current intermediate circuits; (d) the rectified partial currents are controlled individually by transistor units and then; (e) brought together in a first current-carrying line and sent to an electrode of the melting unit and, as a function of the selected type of current, returned over a second or third current-carrying from a second or a third electrode or set of electrodes.