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. 22, 1997
Filed:
Mar. 10, 1995
Takeshi Sawada, Anjo, JP;
Hiroshi Fujita, Kariya, JP;
Hiroya Tsuji, Kariya, JP;
Kanji Takeuchi, Gamagori, JP;
Tsuneyuki Egami, Gamagori, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
An inverter control apparatus for driving a polyphase AC motor for preventing abrupt changes in motor drive currents when switching of one phase is stopped. The apparatus includes a signal generator for generating duty signals of drive signals of respective phases on the basis of a generated reference waveform and a signal modifier for selecting one of the duty signals of one phase, holding it at a predetermined level, and modifying the duty signals of other phases according to the value required to hold the selected duty signal. On the basis of three-phase signal voltage levels, a decision is made on voltage fixing phase intervals by a phase decision circuit, and shift values are determined by an adder at every voltage fixing phase interval. Shift values are selected by a multiplexer according to the outputs of the phase decision circuit and added to triangular wave voltage. Resultant sum values are compared with the three-phase signal voltages to form a three-phase PWM signal.