The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 2020
Filed:
Feb. 02, 2018
Wrightspeed, Inc., Alameda, CA (US);
Ian Wright, Alameda, CA (US);
Wrightspeed, Inc., Alameda, CA (US);
Abstract
Provided are methods for monitoring temperatures of permanent magnets disposed on rotors of permanent magnet motors. Also provided are vehicle drivetrains including permanent magnet motors and controllers operable to monitor temperatures of permanent magnets used in these motors. A magnet temperature is determined based on the rotational speed of the motor and also based on the open circuit voltage of the motor at this rotational speed. The motor may be specifically calibrated to determine its response to magnet temperature changes for any rotational speed. During operation, an inverter connected to the motor and controlling motor's operation may pause its switching for a period of time and check the open circuit voltage of the motor during this period. The corresponding rotor speed may be obtained from other sensors. The controller uses this information to determine the magnet temperature and, in some embodiments, to perform various control operations to avoid overheating.