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. 18, 2020
Filed:
Feb. 01, 2018
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Shingo Ooba, Isesaki, JP;
Masaki Hano, Isesaki, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Abstract
The drive device measures an open-phase voltage in an energization period in pulse width modulation control, and estimates position information of a rotor based on the measured voltage value, to drive the three-phase brushless motor. This drive device is configured so that, when a voltage pulse width of a set duty cycle is less than or equal to a predetermined value, energization with a voltage pulse width of a minimum duty cycle is performed twice in one period of pulse width modulation, and energization with a voltage pulse width of a correction duty cycle is performed twice in next one period of the pulse width modulation, so that energization with a voltage pulse width of a drive duty cycle corresponding to the set duty cycle is performed, on average in two periods.