Power supply system for arc furnace and associated arc furnace and method

Patent metadata

Field	Value
Publication number	US-2025280476-A1
Application number	US-202418949452-A
Country	US
Kind code	A1
Filing date	Nov 15, 2024
Priority date	Dec 5, 2023
Publication date	Sep 4, 2025
Grant date	—

Abstract

Provided is a power supply system for arc furnace and a method for controlling the same, and an arc furnace facility having a power supply system, the power supply system includes a power converter, and a polyphase transformer, a first disconnecting means connecting an input of the power converter to a primary circuit of the transformer, and a second disconnecting means connecting an output of the power converter to the primary circuit of the transformer, the power supply system also includes a first isolation switch and a second isolation switch, and a control circuit.

First claim

1 . A power supply system for arc furnace, the power supply system comprising:
a power converter comprising an input intended to be connected to a polyphase supply grid and an output, and a polyphase transformer comprising a primary circuit and a secondary circuit, a first disconnecting means, and a second disconnecting means, the power supply system further comprises a first isolation switch and a second isolation switch, the first disconnecting means connecting the input of the power converter to a first end of the first isolation switch, the second disconnecting means connecting the output of the power converter to the first end of the first isolation switch, the second end of the first isolation switch being intended to be connected to at least one electrode of the arc furnace, the second isolation switch connecting the first end of the first isolation switch to the primary circuit and the secondary circuit being connected to the second end of the first isolation switch, and a control circuit configured to:
control the power converter to supply the electrode and to stabilize the current and the voltage delivered by the grid to reduce reactions in the grid when the first disconnecting means are open, the second disconnecting means are closed, the first isolation switch is open and the second isolation switch is closed or the first isolation switch is closed and the second isolation switch is open, and
control the power converter to stabilize the current and the voltage delivered by the grid to reduce reactions in the grid when the first disconnecting means are closed, the second disconnecting means are open, the first isolation switch is open and the second isolation switch is closed.

2 . The power supply system according to claim 1 , wherein the power converter comprises an input device, a link circuit comprising a first bus and a second bus, and an output device, wherein:
the input device comprises a plurality of input modules, each input module being connected to the first bus and the second bus and being intended to be connected to a different phase of the supply grid to supply the link circuit with a continuous voltage from the phase of the supply grid, the output device comprises a plurality of output modules, each output module being connected to the first bus and second bus and to the primary circuit to supply the transformer with an alternative voltage from the circuit link.

3 . The power supply system according to claim 2 , wherein each input module comprises:
a leg including:
a first string comprising:
a first set of input switches connected in series, a second set of input switches connected in series, a first connecting node, a second connecting node, and a third connecting node,
the first set of input switches operatively coupling the first bus to the third connecting node, and the first connecting node being disposed between two input switches of the first set of input switches,
the second set of input switches operatively coupling the second bus to the third connecting node, and the second connecting node being disposed between two input switches of the second set of input switches,

a second string comprising:
a first set of input switching units in series, a second set of input switching units in series, and a fourth connecting node,
the first set of input switching units operatively coupling the first connecting node to the fourth connecting node,
the second set of input switching units operatively coupling the second connecting node to the fourth connecting node, and
the fourth connecting node being intended to be connected to the phase of the supply grid,

the control circuit being configured to control the input switches, the input switching units, and the output modules, the third connecting nodes of the input modules being connected together.

4 . The power supply system according to claim 2 , wherein each input module comprises:
a leg including:
a first string comprising:
a first input switch, a second input switch, a first connecting node, a second connecting node, a third connecting node, a first set of input switching units connected in series, and a second set of input switching units connected in series,
the first input switch operatively coupling the first bus to the first connecting node, and the first set of input switching units operatively coupling the first connecting node to the third connecting node,
the second input switch operatively coupling the second bus to the second connecting node, and the second set of input switching units operatively coupling the second connecting node to the third connecting node,

a second string comprising:
a third input switch, a fourth input switch, and a fourth connecting node,
the third input switch operatively coupling the first connecting node to the fourth connecting node, and the fourth input switch operatively coupling the second connecting node to the fourth connecting node,
the fourth connecting node ( 106 ) being intended to be connected to the phase of the supply grid,

the control circuit being configured to control the input switches, the input switching units, and the output modules, the third connecting nodes ( 97 ) of the input modules being connected together.

5 . The power supply system according to claim 2 , wherein each input module comprises:
a leg including:
a first string comprising:
a first input switch, a second input switch, a first connecting node, a second connecting node, a third connecting node, a first set of input switching units connected in series, and a second set of input switching units connected in series,
the first set of input switching units operatively coupling the first bus to the first connecting node, and the first input switch operatively coupling the first connecting node to the third connecting node,
the second set of input switching units operatively coupling the second bus to the second connecting node, and the second input switch operatively coupling the second connecting node to the third connecting node,

a second string comprising:
a third input switch, a fourth input switch, and a fourth connecting node,
the third input switch operatively coupling the first connecting node to the fourth connecting node, and the fourth input switch operatively coupling the second connecting node to the fourth connecting node,
the fourth connecting node being intended to be connected to the phase of the supply grid,

the control circuit being configured to control the input switches, the input switching units, and the output modules, the third connecting nodes of the input modules being connected together.

6 . The power supply system according to claim 2 , wherein each input module comprises a string comprising:
a connecting node being intended to be connected to the phase of the supply grid, a first set of input switching units connected in series, and a second set of input switching units connected in series, the first set of input switching units operatively coupling the first bus to the connecting node, and the second set of input switching units operatively coupling the second bus to the connecting node, and the control circuit being configured to control the input switching units, and the output modules.

7 . The power supply system according to claim 6 , wherein each output module comprises:
a leg including:
a first string comprising:
a first set of output switches connected in series, a second set of output switches connected in series, a first connecting node, a second connecting node, and a third connecting node,
the first set of output switches operatively coupling the first bus to the third connecting node, and the first connecting node being disposed between two output switches of the first se

Assignees

• Ge Energy Power Conversion Technology Ltd

Inventors

• Zhou Zhi
• Basic Duro
• Permuy Alfred
• Mankevich Steven

Classifications

• H05B7/18

  Heating by arc discharge · CPC title

• F27D2099/0021

  Arc heating · CPC title

• F27D2019/0028

  Regulation · CPC title

• F27D11/08

  Heating by electric discharge, e.g. arc discharge · CPC title

• H02M1/0095

  Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck · CPC title