Patents by Inventor Per Rickard Johansson

Per Rickard Johansson 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).

  • Estimation of actual torque in an electrical motor drive
    Patent number: 8558490
    Abstract: It is presented a control device for driving an electric motor, wherein a drive control signal for the electric motor is arranged to be determined using a calculated rotor flux. A direct quadrature, dq, coordinate system relating to a rotor of the electric motor is used. The control device comprises a flux estimator arranged to determine the calculated rotor flux using a quadrature axis voltage, a measured direct axis current, a measured quadrature axis current, an angular velocity, stator resistance and a direct axis inductance and an actual torque calculator arranged to obtain an actual torque estimation using the calculated rotor flux, the measured direct axis current and the measured quadrature axis current. A corresponding method is also presented.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: October 15, 2013
    Assignee: Danaher Motion Stockholm AB
    Inventor: Per Rickard Johansson