Patents by Inventor Mikael Sehlstedt

Mikael Sehlstedt 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: 10962604
    Abstract: An arrangement for injection-based ground fault protection handling including a number of stator windings of an electric machine that are connected to a neutral point, a first transformer including at least one primary winding connected to at least one measurement point of the stator windings and at least one secondary winding for measuring an electrical quantity of the machine at the measurement point. There is also a second transformer having a primary winding connected between the neutral point and a ground potential and a secondary winding for connection to a signal generation and detection unit in order to inject a signal into the neutral point and receive a response. The impedance of the second transformer is in the range of the impedance of the machine.
    Type: Grant
    Filed: July 31, 2019
    Date of Patent: March 30, 2021
    Assignee: ABB SCHWEIZ AG
    Inventors: Stefan Roxenborg, Zoran Gajic, Tord Bengtsson, Mikael Sehlstedt
  • Publication number: 20200103453
    Abstract: An arrangement for injection-based ground fault protection handling including a number of stator windings of an electric machine that are connected to a neutral point, a first transformer including at least one primary winding connected to at least one measurement point of the stator windings and at least one secondary winding for measuring an electrical quantity of the machine at the measurement point. There is also a second transformer having a primary winding connected between the neutral point and a ground potential and a secondary winding for connection to a signal generation and detection unit in order to inject a signal into the neutral point and receive a response. The impedance of the second transformer is in the range of the impedance of the machine.
    Type: Application
    Filed: July 31, 2019
    Publication date: April 2, 2020
    Inventors: Stefan Roxenborg, Zoran Gajic, Tord Bengtsson, Mikael Sehlstedt
  • Patent number: 9041383
    Abstract: A method for linearizing voltage transmission through a transformer including a magnetic core and, input and output windings. A measurement signal is supplied to the input winding at a first frequency and an output signal is measured at the output winding of the transformer, wherein the voltage of the measurement signal may be so low that the transformer operates in a non-linear region. The method includes, for a conditioning signal, selecting a second frequency different from the first frequency, defining an amplitude value of the conditioning signal and supplying the conditioning signal to the input winding at the second frequency with the defined amplitude value so that the transformer operates in its linear region.
    Type: Grant
    Filed: September 18, 2013
    Date of Patent: May 26, 2015
    Assignee: ABB Research Ltd.
    Inventors: Tord Bengtsson, Henrik Johansson, Stefan Roxenborg, Joseph Menezes, Zoltan Nagy, Mikael Sehlstedt
  • Publication number: 20140015510
    Abstract: A method for linearizing voltage transmission through a transformer including a magnetic core and, input and output windings. A measurement signal is supplied to the input winding at a first frequency and an output signal is measured at the output winding of the transformer, wherein the voltage of the measurement signal may be so low that the transformer operates in a non-linear region. The method includes, for a conditioning signal, selecting a second frequency different from the first frequency, defining an amplitude value of the conditioning signal and supplying the conditioning signal to the input winding at the second frequency with the defined amplitude value so that the transformer operates in its linear region.
    Type: Application
    Filed: September 18, 2013
    Publication date: January 16, 2014
    Inventors: Tord Bengtsson, Henrik Johansson, Stefan Roxenborg, Joseph Menezes, Zoltan Nagy, Mikael Sehlstedt