A plant for melting and/or heating metal material includes a furnace, electrical energy feed means and an electric power apparatus connected between the feed means and the furnace; and a corresponding method to power the melting and/or heating plant.

Converter device configured to convert direct voltage and current into alternating voltage and current to be supplied to a load (L). The converter device comprises a bank (11) of capacitors (12), a plurality of power semiconductors (13), a heat sink (14) and a casing (15).

A power supply system for an electric arc furnace includes an AC input connectable to an electrical grid and an AC output for supplying at least one power electrode of the arc furnace; a resonant circuit interconnected between the AC input and the AC output. The resonant circuit includes a controllable bypass switch for connecting and disconnecting a circuit input and a circuit output of the resonant circuit and a capacitor and a main inductor connected in parallel with the bypass switch.

A power supply system for an electric arc furnace includes an AC input connectable to an electrical grid and an AC output for supplying at least one power electrode of the arc furnace; a resonant circuit interconnected between the AC input and the AC output. The resonant circuit includes a controllable bypass switch for connecting and disconnecting a circuit input and a circuit output of the resonant circuit and a capacitor and a main inductor connected in parallel with the bypass switch.

A power supply system for an arc furnace, suitable for converting voltage of a three-phase electric power network into power supply voltage for the arc furnace, has an indirect AC/AC converter having a converter input and a converter output, and a matching apparatus having a matching transformer having a secondary side connectable to the arc furnace and a primary side operatively connected to the converter output. An input transformer group, inserted between the indirect AC/AC converter and the three-phase electric power network, has an input transformer primary side connectable to the three-phase electric power system, an input transformer secondary side connected to the converter input, a first input transformer and a second input transformer. Each of the first and second input transformers has three mutually displaced groups of secondary windings, each of which has a winding for each phase corresponding to a phase of the three-phase electric power network.

A power supply system for an arc furnace, suitable for converting voltage of a three-phase electric power network into power supply voltage for the arc furnace, has an indirect AC/AC converter having a converter input and a converter output, and a matching apparatus having a matching transformer having a secondary side connectable to the arc furnace and a primary side operatively connected to the converter output. An input transformer group, inserted between the indirect AC/AC converter and the three-phase electric power network, has an input transformer primary side connectable to the three-phase electric power system, an input transformer secondary side connected to the converter input, a first input transformer and a second input transformer. Each of the first and second input transformers has three mutually displaced groups of secondary windings, each of which has a winding for each phase corresponding to a phase of the three-phase electric power network.

Methods and systems for managing a heating process are disclosed. An example method can comprise removing a first portion of a material from a vessel and measuring a first parameter of a second portion of the material in the vessel. The second portion of the material can remain in the vessel after the removal of the first portion. The method can comprise, determining a volume of the second portion of the material based on the first parameter, updating a second parameter based on the volume, and performing a process based on the updated second parameter.

Methods and systems for managing a heating process are disclosed. An example method can comprise removing a first portion of a material from a vessel and measuring a first parameter of a second portion of the material in the vessel. The second portion of the material can remain in the vessel after the removal of the first portion. The method can comprise, determining a volume of the second portion of the material based on the first parameter, updating a second parameter based on the volume, and performing a process based on the updated second parameter.

A plant for melting and/or heating metal material includes a furnace, electrical energy feed means and an electric power apparatus connected between the feed means and the furnace; and a corresponding method to power the melting and/or heating plant.

An electric power method for an electric arc furnace includes regulating the electric power frequency of a power voltage and a power current of the electrodes, independently from the mains frequency.