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:
May. 29, 2007
Filed:
Feb. 15, 2005
Junnosuke Nakatsugawa, Hitachi, JP;
Tsuyoshi Tanaka, Hitachi, JP;
Kenji Sakurai, Hitachi, JP;
Tunehiro Endo, Hitachiota, JP;
Junnosuke Nakatsugawa, Hitachi, JP;
Tsuyoshi Tanaka, Hitachi, JP;
Kenji Sakurai, Hitachi, JP;
Tunehiro Endo, Hitachiota, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A control apparatus and a semiconductor apparatus of AC motors capable of reducing torque ripple with a comparatively simple circuit corresponding to a high withstand voltage and capable of driving a motor at high efficiency even when the rotational speed or load has changed. The control apparatus detects first phase signals fixed in relative phase to induced voltages of the motor and current polarity signals, recognizes phase differences between them, generates second phase signals so as to make the phase differences approach zero to drive the motor at high efficiency, generates modulation wave signals having quasi-sinusoidal waveforms or trapezoidal waveforms on the basis of the second phase signals, compares the modulation wave signals with a carrier wave signal, and conducts PWM control on an inverter.