Patents by Inventor Hans C. Christensen

Hans C. Christensen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Power converter arrangement and method
    Patent number: 7667439
    Abstract: A power converter arrangement for connecting an induction generator to an electric power network comprises a first path provided for transferring electric power from the induction generator to the electric power network during a first operation condition, and a second path provided for transferring electric power from the induction generator to the electric power network during a second operation condition, where the first path includes an AC-AC converter and the second path includes a switch. A capacitor arrangement is interconnected between the induction generator and the first and second paths and a first AC reactor device is interconnected between the capacitor arrangement and the first and second paths, where the capacitor arrangement is provided for compensating for a magnetization current of the induction generator.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: February 23, 2010
    Assignee: ABB Research Ltd.
    Inventors: Lars Gertmar, Erik Koldby, Hans C. Christensen, Jouko Niiranen, Leif-Erik Wraae, H{dot over (a)}kan Korske, legal representative
  • Control Method
    Publication number: 20090273187
    Abstract: A generator of a wind turbine is at low power conditions operated as a motor by control of a frequency converter to feed electric power from an electric power transmission network to the generator for raising the speed of the wind rotor above a predetermined level for lubricating rotating parts of a drive train of the wind turbine.
    Type: Application
    Filed: March 27, 2009
    Publication date: November 5, 2009
    Inventors: Lars Gertmar, Leif-Erik Wraae, Helle Wraae, Hans C. Christensen, Juhani Mantere, Erik Koldby
  • Power Converter Arrangement and Method
    Publication number: 20090218820
    Abstract: A power converter arrangement for connecting an induction generator to an electric power network comprises a first path provided for transferring electric power from the induction generator to the electric power network during a first operation condition, and a second path provided for transferring electric power from the induction generator to the electric power network during a second operation condition, where the first path includes an AC-AC converter and the second path includes a switch. A capacitor arrangement is interconnected between the induction generator and the first and second paths and a first AC reactor device is interconnected between the capacitor arrangement and the first and second paths, where the capacitor arrangement is provided for compensating for a magnetization current of the induction generator.
    Type: Application
    Filed: February 27, 2009
    Publication date: September 3, 2009
    Inventors: Lars Gertmar, Erik Koldby, Hans C. Christensen, Jouko Niiranen, Hakan Korske, Leif-Erik Wraae