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:
Dec. 20, 2011
Filed:
Sep. 04, 2009
Katsutoshi Yamanaka, Fukuoka, JP;
Katsutoshi Yamanaka, Fukuoka, JP;
Kabushiki Kaisha Yaskawa Denki, Fukuoka, JP;
Abstract
A power conversion device includes a main circuit that has switches connecting each phase of a three-phase AC power supply to each output phase, an LC filter having a reactor and a capacitor connected between the three-phase AC power supply and each bidirectional switch, and a current detector detecting an input current or a load current, and a four-step commutation device generating four steps on the basis of the polarity of the load current. The four-step commutation device sets times between the steps to a value more than zero so as to inhibit open circuit between output phases and short circuit between power supply phases, and sets the times between the steps in accordance with the polarity of the load current so as to cancel a distortion of an output voltage due to four-step commutation during a PWM cycle.