Patents by Inventor Ulf Axelsson

Ulf Axelsson 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).

  • Patent number: 9028214
    Abstract: The present invention relates to a control system for a wind turbine, comprising an electrical device that is arranged for being used during normal operation of a wind turbine and a power source that is arranged to be used as an emergency power supply to a blade pitch motor, wherein the blade pitch motor is arranged to test at least one property of said power source. The invention also relates to a method for testing a power source.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: May 12, 2015
    Assignee: General Electric Company
    Inventors: Mikael Bjork, Ulf Axelsson
  • Patent number: 8683688
    Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.
    Type: Grant
    Filed: May 13, 2010
    Date of Patent: April 1, 2014
    Assignee: General Electric Company
    Inventors: Ulf Axelsson, Mikael Bjork, Christian Haag
  • Patent number: 8317471
    Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: November 27, 2012
    Assignee: General Electric Company
    Inventors: Ulf Axelsson, Christian Haag, Mikael Björk, Jacob Johannes Nies
  • Publication number: 20120219421
    Abstract: The present invention relates to a control system for a wind turbine, comprising an electrical device that is arranged for being used during normal operation of a wind turbine and a power source that is arranged to be used as an emergency power supply to a blade pitch motor, wherein the blade pitch motor is arranged to test at least one property of said power source. The invention also relates to a method for testing a power source.
    Type: Application
    Filed: August 20, 2010
    Publication date: August 30, 2012
    Inventors: Mikael Bjork, Ulf Axelsson
  • Publication number: 20120180314
    Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.
    Type: Application
    Filed: May 13, 2010
    Publication date: July 19, 2012
    Inventors: Ulf Axelsson, Mikael Bjork, Christian Haag
  • Publication number: 20120134807
    Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.
    Type: Application
    Filed: November 29, 2011
    Publication date: May 31, 2012
    Inventors: Ulf AXELSSON, Christian HAAG, Mikael BJÖRK, Jacob Johannes NIES
  • Publication number: 20120027589
    Abstract: A wind turbine (10) is provided. The wind turbine includes a rotor (18), at least one rotor blade (22) coupled to the rotor, and a yaw system (92). The yaw system (92) includes at least one yaw motor (94) for adjusting a yaw angle of the wind turbine (10). The yaw system (92) is configured for generating a yaw drive signal corresponding to at least one of: i) a property from the at least one yaw motor (94); or ii) a control signal for operating the at least one yaw motor. The wind turbine (10) further includes an asymmetric load control assembly (100) configured to receive the yaw drive signal. The asymmetric load control assembly (100) is further configured to mitigate an asymmetric load acting on the rotor (18) using the yaw drive signal. A control system for operating a wind turbine (10) and a method thereof are also provided.
    Type: Application
    Filed: May 26, 2011
    Publication date: February 2, 2012
    Inventors: Christian Haag, Ulf Axelsson, Mikael Bjõrk, Christoph Schulten, Gert Torbohm
  • Patent number: 6137791
    Abstract: A roaming mechanism enabling a mobile station to roam between a first data packet network utilizing a Mobile IP Method (MIM) and a second data packet network utilizing a Personal Digital Cellular Mobility Method (PMM) is disclosed. A foreign agent (FA) is introduced into the PMM network for enabling a mobile station associated with the MIM network and currently roaming within the PMM network to communicate packet data with an associated home agent (HA). A home agent (HA) is further introduced into the PMM network for enabling a mobile station associated with the PMM network and currently roaming within the MIM network to communicate packet data with an associated FA or Mobile IP Client Emulator (MICE) currently serving the roaming mobile station.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: October 24, 2000
    Inventors: Lars Frid, Arne Pehrsson, Martin Backstrom, Dick Andersson, Ulf Axelsson, Ulf Olsson