DEVICE AND METHOD FOR CONTROLLING AN ELECTRIC ARC FURNACE IN THE INITIAL PHASE OF A MELTING PROCESS

摘要

Disclosed is a device and a method for regulating an electric arc furnace (10) in the initial phase of a smelting process. A sensor (16) for measuring the present voltage and a sensor (15) for measuring the presently flowing current are provided in each line (7) of the electric arc furnace (10). The actual impedance (Zist) is time-dependently calculated by a control and regulating unit (30). An on-load tap changer (20) that is constructed as a semiconductor tap changer, is assigned to a furnace transformer (6) with a primary side (6P) and a secondary side (6S). The semiconductor tap changer (20) realizes a cycle time of a few milliseconds.