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:
Jun. 30, 2026
Filed:
Feb. 09, 2022
Hitachi Astemo, Ltd., Hitachinaka, JP;
Takaya Tsukagoshi, Hitachinaka, JP;
Takafumi Hara, Tokyo, JP;
Katsuhiro Hoshino, Hitachinaka, JP;
Shigehisa Aoyagi, Hitachinaka, JP;
HITACHI ASTEMO, LTD., Hitachinaka, JP;
Abstract
A motor control device controls an AC motor connected to a power transformer. The transformer transforms power from DC to AC and outputs rotational driving force generated using AC power via a speed reducer. The device includes a carrier generator that generates a carrier wave, a frequency adjuster that adjusts a frequency of the carrier wave, and a gate signal generator that performs pulse width modulation on a voltage command according to a torque command using the carrier wave and generates a gate signal for controlling the transformer. The frequency adjuster changes a phase difference between the voltage command and the carrier wave based on the torque command and a rotational speed of the AC motor, and adjusts the frequency such that difference between a meshing frequency of the speed reducer and a harmonic component of a harmonic current according to the voltage command falls within a predetermined range.