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:
Jul. 01, 2014
Filed:
Jul. 26, 2011
Yoshitaka Iwaji, Hitachinaka, JP;
Shigehisa Aoyagi, Hitachinaka, JP;
Kazuaki Tobari, Hitachiota, JP;
Ryoichi Takahata, Hitachi, JP;
Yoshitaka Iwaji, Hitachinaka, JP;
Shigehisa Aoyagi, Hitachinaka, JP;
Kazuaki Tobari, Hitachiota, JP;
Ryoichi Takahata, Hitachi, JP;
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, JP;
Hitachi Car Engineering Co., Ltd., Hitachinaka-shi, JP;
Abstract
A synchronous electric motor drive system capable of driving at speeds near zero is provided. An energization mode determination unit switches six energization modes successively based on a terminal potential detected of the de-energized phase of a three-phase synchronous electric motor or on a stator winding wire connection point potential (neutral point potential) detected of the three-phase synchronous transmission unit. A voltage command correction unit corrects by a correction amount ΔV an applied voltage command destined for the synchronous electric motor to supply the synchronous electric motor with a repeated waveform of a positive pulse, negative pulse, and zero voltage as a line voltage waveform of the energized phases in each of the six energization modes, the positive pulse voltage being polarized to cause the synchronous electric motor to generate a forward rotation torque, the negative pulse voltage causing the synchronous electric motor to generate a reverse rotation torque.