Patents by Inventor James J. Sewell

James J. Sewell 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).

  • Power-loss ridethrough system and method
    Patent number: 10738784
    Abstract: A method of operating an electric induction motor with a variable-speed drive includes determining a voltage level on a DC bus for the drive, and measuring a first magnitude of magnetic flux from a stator of the normally-operating electric motor, determining a normal flux level. The method includes disabling a first output to the drive when the DC bus voltage is less than a first threshold level. The method includes measuring a magnetic flux feedback signal having a phase and second magnitude, estimating a speed of the electric motor, and configuring a second output signal for the drive when the DC bus voltage is greater than a second threshold level. The second output signal matches a signal from the second magnitude and a phase of magnetic flux. The method includes enabling the drive output to restart the electric motor when the magnetic flux is greater than a third threshold value.
    Type: Grant
    Filed: September 5, 2018
    Date of Patent: August 11, 2020
    Assignee: Unico, LLC
    Inventor: James J. Sewell
  • Power-loss Ridethrough System and Method
    Publication number: 20190078572
    Abstract: A method of operating an electric induction motor with a variable-speed drive includes determining a voltage level on a DC bus for the drive, and measuring a first magnitude of magnetic flux from a stator of the normally-operating electric motor, determining a normal flux level. The method includes disabling a first output to the drive when the DC bus voltage is less than a first threshold level. The method includes measuring a magnetic flux feedback signal having a phase and second magnitude, estimating a speed of the electric motor, and configuring a second output signal for the drive when the DC bus voltage is greater than a second threshold level. The second output signal matches a signal from the second magnitude and a phase of magnetic flux. The method includes enabling the drive output to restart the electric motor when the magnetic flux is greater than a third threshold value.
    Type: Application
    Filed: September 5, 2018
    Publication date: March 14, 2019
    Applicant: Unico, Inc.
    Inventor: James J. Sewell
  • Apparatus for continued operation of an electric motor during an interruption in input power
    Patent number: 8779709
    Abstract: An apparatus is provided for controlling operation of an electric motor through use of an additional power storage arrangement connected across the DC busses of a motor drive and controlling the speed of the motor. The additional power storage arrangement includes an additional capacitor arrangement and a rate limiting arrangement in a series circuit relationship with one another.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: July 15, 2014
    Assignee: Unico, Inc.
    Inventors: Michael O. Lucas, Rick L. Tennessen, Harry W. Schulz, William S. Hammel, James J. Sewell
  • Apparatus for Continued Operation of an Electric Motor During an Interruption in Input Power
    Publication number: 20130043813
    Abstract: An apparatus is provided for controlling operation of an electric motor through use of an additional power storage arrangement connected across the DC busses of a motor drive and controlling the speed of the motor. The additional power storage arrangement includes an additional capacitor arrangement and a rate limiting arrangement in a series circuit relationship with one another.
    Type: Application
    Filed: August 2, 2012
    Publication date: February 21, 2013
    Inventors: Michael O. Lucas, Rick L. Tennessen, Harry W. Schulz, William S. Hammel, James J. Sewell