US Patent No. 10,716,176

APPARATUS AND METHOD FOR DYNAMICALLY ADJUSTING AN ELECTRIC ARC FURNACE


Patent No. 10,716,176
Issue Date July 14, 2020
Title Apparatus And Method For Dynamically Adjusting An Electric Arc Furnace
Inventorship Arno Doebbeler, Herzogenaurach (DE)
Werner Hartmann, Weisendorf (DE)
Martin Hergt, Nuremberg (DE)
Juergen Rupp, Erlangen (DE)
Assignee SIEMENS AKTIENGESELLSCHAFT, Munich (DE)

Claim of US Patent No. 10,716,176

1. An electric arc furnace comprising:a power supply system with at least one system phase for applying an alternating electrical voltage and an arc current;
a furnace electrode fed by the power supply system;
a control loop device comprising an electrical converter configured for reverse feedback of an amplitude and/or a frequency of the alternating voltage to an amplitude and/or a frequency of the arc current, wherein the electrical converter comprises a two-port network comprising an input port and an output port;
the power supply system attached to the input port;
a melting furnace power supply connected to the output port;
a primary circuit of a first transformer electrically connected to the output port;
a secondary circuit of the first transformer electrically connected to the furnace electrode;
a primary coil of a second transformer electrically connected in parallel to the input port of the electrical converter; and
a secondary coil of the second transformer electrically connected in series with a secondary coil of the first transformer.