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. 13, 2019
Filed:
Jan. 05, 2017
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Takeshi Umetsu, Isesaki, JP;
Naoki Okamoto, Isesaki, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Abstract
Before sensorless control is performed on a three-phase brushless motor by sequentially switching between six energization modes each for selecting two phases to be energized from the three phases, the initial position of the rotor is estimated based on a change in a second induced voltage by: momentarily energizing the three-phase brushless motor according to each of the six energization modes, and detecting six first induced voltages each generated in a non-energized phase by the energization; calculating three induced voltage differences corresponding respectively to three non-energized phases, each induced voltage difference being a difference between two of the six first induced voltages that are detected during energization according to two energization modes that share a non-energized phase; and energizing the three-phase brushless motor according a predetermined energization mode selected based on the three induced voltage differences, and detecting the second induced voltage generated in a non-energized phase by the energization.