Patents by Inventor Derek Lehmann

Derek Lehmann 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 system for controlling braking of an electric motor
    Patent number: 12413165
    Abstract: In accordance with one embodiment, a method of controlling a braking of a rotor of an electric motor comprises operating an electric motor in a first mode at an inefficient operating point or inefficient operating curve of a quadrature-axis current versus a direct-axis current such that the braking of the electric motor occurs at a rate based on a rate proportional to or less than the total available power losses in the motor, the inverter, or both. The electric motor is operated in the first mode until the observed rotor speed of the electric motor is less than or equal to a threshold speed; thereafter a multi-phase short circuit can be applied.
    Type: Grant
    Filed: July 13, 2023
    Date of Patent: September 9, 2025
    Assignee: Deere & Company
    Inventors: Scott C. Johnson, Andrew W. Kelly, Derek Lehmann
  • METHOD AND SYSTEM FOR CONTROLLING BRAKING OF AN ELECTRIC MOTOR
    Publication number: 20240297602
    Abstract: In accordance with one embodiment, a method of controlling a braking of a rotor of an electric motor comprises operating an electric motor in a first mode at an inefficient operating point or inefficient operating curve of a quadrature-axis current versus a direct-axis current such that the braking of the electric motor occurs at a rate based on a rate proportional to or less than the total available power losses in the motor, the inverter, or both. The electric motor is operated in the first mode until the observed rotor speed of the electric motor is less than or equal to a threshold speed; thereafter a multi-phase short circuit can be applied.
    Type: Application
    Filed: July 13, 2023
    Publication date: September 5, 2024
    Inventors: Scott C. Johnson, Andrew W. Kelly, Derek Lehmann