Electrode vibration detection modules (EVDM) and methods of detecting vibration of an electrode of an electric arc furnace (EAF) using an EVDM are provided, in which the EVDM receives and/or ascertains waveform signals corresponding to voltage values and current values associated with an electrode voltage measured between the electrode and the bottom of the EAF shell (electrode voltage) and the electrical current passing through the electrode and is configured to identify conditions for electrode vibration based, at least in part, on the waveform signals and to trigger an alarm and/or modify the operation of the EAF by adjusting the location of the electrode in the EAF.

A non-linear load in the form of an arc furnace with an upstream furnace transformer is supplied with electric power from a power supply device with a plurality of converter units. The converter units have a plurality of main modules with inputs connected to a respective phase of a three-phase grid. The converter units have a common star point between the main modules and the primary side of the furnace transformer. Each main module has a series circuit with a coupling inductance and a plurality of submodules. The submodules have a bridge circuit with four self-commutated semiconductor switches and a bridge path with a storage capacitor between input and output. The semiconductor switches of the submodules can each be switched independently of the semiconductor switches of the other submodules of the same main module and of the other main modules.

A non-linear load in the form of an arc furnace with an upstream furnace transformer is supplied with electric power from a power supply device with a plurality of converter units. The converter units have a plurality of main modules with inputs connected to a respective phase of a three-phase grid. The converter units have a common star point between the main modules and the primary side of the furnace transformer. Each main module has a series circuit with a coupling inductance and a plurality of submodules. The submodules have a bridge circuit with four self-commutated semiconductor switches and a bridge path with a storage capacitor between input and output. The semiconductor switches of the submodules can each be switched independently of the semiconductor switches of the other submodules of the same main module and of the other main modules.

A Vacuum Arc Remelting controller apparatus wherein process control is accomplished primarily through control of pool power. Pool power being defined as the total energy flux into a top ingot surface of the VAR ingot. The controller apparatus of the present invention comprises a controller computer that transmits commands to the host furnace through an ethernet connection.

A Vacuum Arc Remelting controller apparatus wherein process control is accomplished primarily through control of pool power. Pool power being defined as the total energy flux into a top ingot surface of the VAR ingot. The controller apparatus of the present invention comprises a controller computer that transmits commands to the host furnace through an ethernet connection.

An electric power supply apparatus for a direct current user device includes an electric power supply supplying a mains voltage and a mains current and a static power converter to transform a direct electric voltage into a direct electric voltage of a different value. The static power converter is connected to the electric power supply by a respective input connection circuit and to the user device by a respective output connection circuit.

An electric power supply apparatus for a direct current user device includes an electric power supply supplying a mains voltage and a mains current and a static power converter to transform a direct electric voltage into a direct electric voltage of a different value. The static power converter is connected to the electric power supply by a respective input connection circuit and to the user device by a respective output connection circuit.

An electrical arrangement for an electric arc furnace (1) operated with alternating current has a converter (2) which converts mains voltage (U), having a mains frequency (f), of a supply grid (3) into primary voltage (U) having a furnace frequency (f). A furnace transformer (4) of the electrical arrangement transforms the primary voltage (U) into a secondary voltage (U). The secondary voltage (U) is supplied to a number of electrodes (6) of the electric arc furnace (1). The electrodes (6) are arranged in a furnace vessel (8) of the electric arc furnace (1). They apply electric arcs (10) to a melt material (9) in the furnace vessel (8). The secondary voltage (U) is also supplied to a capacitor assembly (7) which is on the output side of the furnace transformer (4) and to which the furnace transformer (4) is connected on the output side. The converter (2) is controlled by a control device (5) such that a primary voltage (U) output from the converter (2) to the furnace transformer (4) has a furnace frequency (f) which is at least ten times the mains frequency (f) and/or is greater than 1 kHz.

An electrical arrangement for an electric arc furnace (1) operated with alternating current has a converter (2) which converts mains voltage (U), having a mains frequency (f), of a supply grid (3) into primary voltage (U) having a furnace frequency (f). A furnace transformer (4) of the electrical arrangement transforms the primary voltage (U) into a secondary voltage (U). The secondary voltage (U) is supplied to a number of electrodes (6) of the electric arc furnace (1). The electrodes (6) are arranged in a furnace vessel (8) of the electric arc furnace (1). They apply electric arcs (10) to a melt material (9) in the furnace vessel (8). The secondary voltage (U) is also supplied to a capacitor assembly (7) which is on the output side of the furnace transformer (4) and to which the furnace transformer (4) is connected on the output side. The converter (2) is controlled by a control device (5) such that a primary voltage (U) output from the converter (2) to the furnace transformer (4) has a furnace frequency (f) which is at least ten times the mains frequency (f) and/or is greater than 1 kHz.

An electric power apparatus for an electric arc furnace comprises at least one electrode and is connectable to a power network to supply to the electrode the electric energy to generate an electric arc to melt a metal mass. The apparatus comprises an electric regulation unit interposed and connected to the power network and to the electrode and configured to regulate at least one electric quantity for powering the electrode. The apparatus comprises at least one detection device to detect the electric quantity, interposed between the electrode and the electric regulation unit, a positioning device to move the at least one electrode nearer to/away from the metal mass to be melted and a control and command unit.