Electric arc furnace controller

An AC electric arc furnace comprising:

• a container for receiving metal;
• an electrode spaced apart from the container, the electrode and the container including inputs for coupling to an AC power source for generating an electric discharge from the electrode;
• and
• a flicker controller for reducing flicker induced in the power source, the flicker controller comprising a switch electrically connected in series with the power source and the electrode and including a gating input for controlling the application of AC power to the electrode, a reactive element electrically coupled between the power source and the electrode for providing a reactive current path between the power source and the electrode independent of a conductive state of the switch, and a control system for applying gating signals to the gating input for maintaining a magnitude of reactive current flow through the electrode substantially constant.

A real power fluctuation controller for controlling changes in real power demand imposed on a power source when a switched load is coupled to and uncoupled from the power source, the real power retarding circuit comprising:

• a switch electrically connect in series with the power source and the load, the switch including a gating input for controlling a conduction interval of the switch;
• a resistive element coupled in parallel with the switch for retarding a flow of real current drawn by the load when the switch is in a non-conductive state;
• and
• a control system for applying signals to the gating input for controlling a magnitude of current drawn by the load.