Patents by Inventor Goeran Lindahl

Goeran Lindahl 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).

  • Method for detection of a ground fault, which occurs in the vicinity of a neutral point in an electrical device, as well as an apparatus for carrying out the method
    Patent number: 7142403
    Abstract: The invention relates to a method for detection of a ground fault (18), which occurs in the vicinity of a neutral point (22), in a polyphase electrical device which is operated at a fundamental frequency, in particular an electrical machine (10) or a transformer which has a number of windings (11, 12, 13), which are associated with the individual phases, one end of each of which windings (11, 12, 13) is connected to the neutral point (22) and the other end of each of which windings (11, 12, 13) is connected directly to a power supply network via a power supply system connection (14, 15, 16). Simple and reliable detection is achieved in that the change in the physical variables which is associated with a ground fault (18) is measured in the immediate vicinity of the ground fault (18), and is evaluated.
    Type: Grant
    Filed: May 18, 2004
    Date of Patent: November 28, 2006
    Assignee: Alstom Technology Ltd.
    Inventors: Goeran Lindahl, Erland Soerensen
  • Method for detection of a ground fault, which occurs in the vicinity of a neutral point in an electrical device, as well as an apparatus for carrying out the method
    Publication number: 20040264079
    Abstract: The invention relates to a method for detection of a ground fault (18), which occurs in the vicinity of a neutral point (22), in a polyphase electrical device which is operated at a fundamental frequency, in particular an electrical machine (10) or a transformer which has a number of windings (11, 12, 13), which are associated with the individual phases, one end of each of which windings (11, 12, 13) is connected to the neutral point (22) and the other end of each of which windings (11, 12, 13) is connected directly to a power supply network via a power supply system connection (14, 15, 16). Simple and reliable detection is achieved in that the change in the physical variables which is associated with a ground fault (18) is measured in the immediate vicinity of the ground fault (18), and is evaluated.
    Type: Application
    Filed: May 18, 2004
    Publication date: December 30, 2004
    Inventors: Goeran Lindahl, Erland Soerensen