Electric power supply apparatus for a high-power user device

An electric power supply apparatus for an electric furnace for steel industry applications, comprising:

• means for connection to an electricity grid for supplying a mains voltage and a mains current,
• at least one electric line for the connection between said means for connection to the electricity grid and said electric furnace, and
• a power supply system able to power said electric furnace with alternating current and connected between said electricity grid and said electric furnace, wherein said power supply system comprises a plurality of power supply modules connected in parallel to each other, to the electricity grid, and to the electric furnace, each of the power supply modules comprising a first part configured to transform the electrical energy in alternating current supplied by the electricity grid into electrical energy in direct current, the first part comprising at least one transformer provided with at least one transformer primary connected to at least one transformer secondary, and at least one rectifier connected to the transformer secondary, and a second part configured to transform the electrical energy in direct current into electrical energy in alternating current, the second part comprising at least one converter connected to said at least one rectifier,
• wherein said first part and said second part of each power supply module are physically distanced from each other and connected to each other by an intermediate circuit in direct current connected between said at least one rectifier and said at least one converter, said intermediate circuit comprising one or more segments of line made with a superconductor cable, and
• wherein said electricity grid is of the three-phase type and each of the power supply modules is provided with a transformer secondary, a rectifier and a converter for each phase of said electricity grid;
• and
• wherein the at least one transformer is a medium voltage/medium voltage transformer and said electric apparatus comprises at least one high voltage/medium voltage transformer located downstream of said electricity grid and upstream of said medium voltage/medium voltage transformer, wherein said medium voltage/medium voltage transformer and said high voltage/medium voltage transformer are connected by a segment of line made with at least one superconductor cable.

An electric power supply apparatus for an electric furnace for steel industry applications, comprising:

• means for connection to an electricity grid for supplying a mains voltage and a mains current,
• at least one electric line for the connection between said means for connection to the electricity grid and said electric furnace, and
• a power supply system able to power said electric furnace with alternating current and connected between said electricity grid and said electric furnace, wherein said power supply system comprises a plurality of power supply modules connected in parallel to each other, to the electricity grid, and to the electric furnace, each of the power supply modules comprising a first part configured to transform the electrical energy in alternating current supplied by the electricity grid into electrical energy in direct current, the first part comprising at least one transformer provided with at least one transformer primary connected to at least one transformer secondary, and at least one rectifier connected to the transformer secondary, and a second part configured to transform the electrical energy in direct current into electrical energy in alternating current, the second part comprising at least one converter connected to said at least one rectifier,
• wherein said first part and said second part of each power supply module are physically distanced from each other and connected to each other by an intermediate circuit in direct current connected between said at least one rectifier and said at least one converter, said intermediate circuit comprising one or more segments of line made with a superconductor cable, and
• wherein said electricity grid is of the three-phase type and each of the power supply modules is provided with a transformer secondary, a rectifier and a converter for each phase of said electricity grid;
• wherein at least the first part of each power supply module is positioned inside a first building and at least the second part of each power supply module is positioned inside a second building, said parts of each power supply module being connected by said one or more segments of line made with at least one superconductor cable;
• wherein said first part positioned in the first building comprises the transformers and the rectifiers of each power supply module, while said second part positioned in the second building comprises the converters and the segments of line which carry the current from said converters to the electric furnace;
• and
• further wherein the second part of each power supply module further comprises inductors positioned in the second building.