Furnace power supply apparatus, system for the power supply of a furnace, furnace, use of the furnace power supply apparatus and operating method

System for the supply of at least one electric arc furnace and/or electric reduction furnace and/or submerged arc-resistance furnace with electric energy,

• wherein the system is connectable to at least one three phase power network;
• wherein the system is connectable to at least one electrode of at least one electric arc furnace and/or electric reduction furnace and/or submerged arc-resistance furnace;
• characterized by the following features:
• the system comprises a plurality of furnace power supply apparatuses according to one of the preceding claims, and
• wherein the plurality of furnace power supply apparatuses are connected in parallel to each other.

Method for operating an electric arc furnace or an electric reduction furnace or a submerged arc-resistance furnace that comprises a furnace supply apparatus, characterized in that the ratio of active power flow and reactive power flow is controlled and/or regulated by influencing a control quantity of an AC/DC converter circuit and/or of a DC/DC converter circuit and/or of a DC/AC converter circuit and/or of a DC chopper circuit,

• wherein the furnace power supply apparatus is connectable to a three phase power network;
• wherein the furnace power supply apparatus is connectable to at least one electrode of the electric arc furnace, electric reduction furnace or the submerged arc-resistance furnace,
• wherein the furnace power supply apparatus comprises:
• at least one AC/DC converter circuit connectable to the three phase power network and configured to rectify an alternating current of at least one phase of the three phase power network, wherein the three phase power network has a voltage level higher than or equal to 1000 VAC, and
• at least one DC/DC converter circuit configured to handle a voltage level higher than or equal to 500 VDC, wherein the DC/DC converter circuit is connected to the direct current side of the AC/DC converter circuit.