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:
Nov. 17, 2020
Filed:
Aug. 24, 2016
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
HITACHI AUTOMOTIVE SYSTEMS, LTD., Hitachinaka-Shi, JP;
Abstract
The present invention relates to a motor driving device and a method for measuring a phase current in a motor driving device, and specifically relates to a technique of measuring three phase currents of a three-phase brushless motor using a current sensor for measuring the DC bus current in the inverter. The control unit according to the present invention shifts a pulse phase of a PWM pulse such that pulse phases of the three phase PWM pulses in a first PWM cycle of the PWM control differ from those in a second PWM cycle of the PWM control, and measures the three phase currents from the output of the current sensor in these two first and second PWM cycles. The control unit calculates an offset error of the current sensor from these three phase current measurements and learns a correction value used for performing offset correction on the electric-current measurement.