Patents Assigned to Inverpower Controls Ltd.
  • Patent number: 6274851
    Abstract: An electric arc furnace includes a container for receiving metal, an electrode spaced apart from the container, and an electrical power source coupled to the electrode and the container for generating an electrical discharge between the electrode and the container for melting the metal in the container. The arc furnace includes a flicker controller for reducing flicker induced in the power source by the electric arc furnace. The flicker controller consists of a switch electrically connected between the power source and the electrode, and a control system coupled to the switch. The switch includes a gating input for controlling a conduction interval of the switch, and the control system applies gating signals to the gating input for maintaining a magnitude of reactive current flow through the arc furnace substantially constant.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: August 14, 2001
    Assignee: Inverpower Controls Ltd.
    Inventors: Joseph A. Mulcahy, Dawit Tadesse, Janos Rajda, Hassan Ali Kojori
  • Patent number: 6137277
    Abstract: A static voltage regulator consists of a booster transformer, a regulator transformer, an electronic switching system and a control system. The booster transformer includes a booster primary winding and a booster secondary winding. The booster secondary is provided in series with the input and output terminals of the regulator so as to produce an output voltage. The regulator transformer includes a regulator primary winding and a regulator secondary winding. The regulator primary is electrically coupled to the output. The electronic switching system is coupled between the regulator secondary and the booster primary for providing a voltage to the booster primary. The control system includes a voltage sensor for sensing a voltage at the input, and a gating system coupled to the switching system for switching the output voltage in response to changes in the sensed input voltage.
    Type: Grant
    Filed: October 29, 1999
    Date of Patent: October 24, 2000
    Assignee: Inverpower Controls Ltd.
    Inventors: Janos Rajda, Shashi Dewan, Rusong Wu, Jianping Li
  • Patent number: 5991327
    Abstract: In an electric arc furnace having a power source for applying at least one AC/DC voltage to at least one electrode, and the electrode being spaced apart from a grounded container for receiving scrap metal, wherein the application of the at least one AC/DC voltage to the at least one electrode causes generation of an arc between the electrode and the container for melting the scrap metal, a predictive line controller comprising a plurality of AC switches intermediate the power source and the electrode, and a central controller for monitoring the at least one AC/DC voltage and generating a signal model thereof, and in response generating and applying a plurality of gating signals to the plurality of AC switches, the gating signals being delayed by respective predetermined amounts based on the model, for causing the plurality of AC switches to gate the at least one AC/DC voltage in accordance with the model so as to minimize flicker in the electric arc furnace.
    Type: Grant
    Filed: October 26, 1995
    Date of Patent: November 23, 1999
    Assignee: Inverpower Controls Ltd.
    Inventor: Hassan Ali Kojori