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.

The present disclosure provides a circular electric furnace, and electrode arrangement structure thereof. The electrode arrangement structure of the circular electric furnace comprises: 2n electrodes (11-16) and n single-phase transformers (40) each including two output ends, wherein the 2n electrodes (11-16) are respectively connected to the output ends of the n single-phase transformers (40), and n is an integer2. The electrode arrangement structure of the circular electric furnace of the present disclosure comprises 2n electrodes (11-16) and n single-phase transformers, with n2. That is, the structure comprises at least 4 electrodes and 2 single-phase transformers (40), and one single-phase transformer (40) is connected to two electrodes. In this way, the numbers of electrodes and transformers in the circular electric furnace are effectively increased, and the restriction of a conventional circular electric furnace which can only accommodate three electrodes and one transformer is eliminated, thus effectively increasing the electric power of a circular electric furnace.

The present disclosure provides a circular electric furnace, and electrode arrangement structure thereof. The electrode arrangement structure of the circular electric furnace comprises: 2n electrodes (11-16) and n single-phase transformers (40) each including two output ends, wherein the 2n electrodes (11-16) are respectively connected to the output ends of the n single-phase transformers (40), and n is an integer2. The electrode arrangement structure of the circular electric furnace of the present disclosure comprises 2n electrodes (11-16) and n single-phase transformers, with n2. That is, the structure comprises at least 4 electrodes and 2 single-phase transformers (40), and one single-phase transformer (40) is connected to two electrodes. In this way, the numbers of electrodes and transformers in the circular electric furnace are effectively increased, and the restriction of a conventional circular electric furnace which can only accommodate three electrodes and one transformer is eliminated, thus effectively increasing the electric power of a circular electric furnace.

Provided is an AC-DC-AC converter for delivering power to a load from a power source that includes a front-end converter, a load-end converter, and a DC link. At least one of the front-end converter and the load-end converter is a hybrid modular multilevel converter. The load-end converter or the front-end converter employ controllable switches in order to either direct or regulate power. The controllable switches can be controlled in order to modify the real and reactive power used/consumed or re-generated by the load (e.g., the electric arc furnace). The load-end converter control and the front-end converter control are independent or decoupled.

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.

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.

The method for adjusting the impedance of one or more phases of a secondary circuit of an electric furnace, in order to limit the unbalance between the phases themselves comprises the transformer (31), a variable impedance secondary circuit for one or more phases (F1, F2, F3), the rigid and fixed interconnection (32) for each phase (F1, F2, F3) connected to the transformer, the flexible cables (33) connected by means of the proximal end to the fixed interconnection (32), the electrode holding arms (34) connected to the distal end of the flexible cables (33), the conductive electrodes (35) fixed to the respective electrode holding arms (34). The rigid and fixed interconnection (32) of a phase (F1, F2, F3) comprises at least one turn (11), wherein the impedance is either continuously or discreetly variable in order to obtain the desired impedance value.

The method for adjusting the impedance of one or more phases of a secondary circuit of an electric furnace, in order to limit the unbalance between the phases themselves comprises the transformer (31), a variable impedance secondary circuit for one or more phases (F1, F2, F3), the rigid and fixed interconnection (32) for each phase (F1, F2, F3) connected to the transformer, the flexible cables (33) connected by means of the proximal end to the fixed interconnection (32), the electrode holding arms (34) connected to the distal end of the flexible cables (33), the conductive electrodes (35) fixed to the respective electrode holding arms (34). The rigid and fixed interconnection (32) of a phase (F1, F2, F3) comprises at least one turn (11), wherein the impedance is either continuously or discreetly variable in order to obtain the desired impedance value.

An electric arc furnace (EAF) including a raw material container, a set of electrodes, a set of electrical potential transformers, and a reference signal verification device. The set of electrodes are configured to be controllably extended toward the raw material container. The set of electrical potential transformers are correspondingly coupled to the set of electrodes. The reference signal verification device is configured to carry out the steps of reading a reference signal value coming from the raw material container; comparing the reference signal value to an approximated value; and determining that there is a loss of the reference signal if the reference signal value is not within a predetermined amount of the approximated value.

An electric arc furnace (EAF) including a raw material container, a set of electrodes, a set of electrical potential transformers, and a reference signal verification device. The set of electrodes are configured to be controllably extended toward the raw material container. The set of electrical potential transformers are correspondingly coupled to the set of electrodes. The reference signal verification device is configured to carry out the steps of reading a reference signal value coming from the raw material container; comparing the reference signal value to an approximated value; and determining that there is a loss of the reference signal if the reference signal value is not within a predetermined amount of the approximated value.