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

A power supply system for arc furnace, the power supply system comprising:

• a power converter comprising an input connected to a polyphase supply grid and an output, and
• a polyphase transformer comprising a primary circuit and a secondary circuit connected to at least one electrode of the arc furnace,
• wherein the power supply system further comprises first disconnecting means connecting the input of the power converter to the primary circuit, second disconnecting means connecting the output of the power converter to the primary circuit, and the power supply system further comprises a control circuit configured:
• to control the power converter to supply the electrode and to stabilize the current and the voltage delivered by the polyphase supply grid to reduce reactions in the polyphase supply grid wen the first disconnecting means are open and the second disconnecting means are closed, and
• to control the power converter to stabilize the current and the voltage delivered by the polyphase supply grid to reduce reactions in the polyphase supply grid when the first disconnecting means are closed and the second disconnecting means are open.