Patents by Inventor Pekka Varis

Pekka Varis 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 and apparatus for detecting ground fault
    Patent number: 8203346
    Abstract: Method and apparatus for detecting a ground fault, the apparatus including diagnostics unit arranged to monitor a sum current of output phases of a frequency converter, diagnostics unit arranged to detect a ground fault, if the sum current exceeds a predetermined threshold value, and diagnostics unit for performing the initial setting of the threshold value, the diagnostic unit being arranged to determine the value of the sum current when the frequency converter starts up and to set the threshold value so that it is greater than the predetermined value of the sum current.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: June 19, 2012
    Assignee: ABB Oy
    Inventors: Vesa Tilhonen, Pekka Varis
  • METHOD AND APPARATUS FOR DETECTING GROUND FAULT
    Publication number: 20090160453
    Abstract: Method and apparatus for detecting a ground fault, the apparatus comprising means arranged to monitor a sum current of output phases of a frequency converter, means arranged to detect a ground fault, if the sum current exceeds a predetermined threshold value, and means for performing the initial setting of the threshold value, the means being arranged to determine the value of the sum current when the frequency converter starts up and to set the threshold value so that it is greater than the predetermined value of the sum current.
    Type: Application
    Filed: December 18, 2008
    Publication date: June 25, 2009
    Applicant: ABB Oy
    Inventors: Vesa TIIHONEN, Pekka Varis