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:
Feb. 26, 2002
Filed:
Apr. 30, 2001
Toshihiro Sawa, Fukuoka, JP;
Xiaorong Xia, Fukuoka, JP;
Sadao Ishii, Fukuoka, JP;
Eiji Yamamoto, Fukuoka, JP;
Hidenori Hara, Fukuoka, JP;
Kabushiki Kaisha Yaskawa Denki, Fukuoka, JP;
Abstract
A protection apparatus and a protection method of a PWM cycloconverter wherein when the PWM cycloconverter is shut off, a surge voltage or an overcurrent is not produced on the output side are provided. A protection apparatus of a PWM cycloconverter is made up of fault detection means for detecting a fault of the PWM cycloconverter, operation stop means for turning off at least some of the uni-directional semiconductor switches to of the PWM cycloconverter if a fault signal occurs, continuous flow means for allowing a load current of the PWM cycloconverter to continuously flow if at least some output phases of the PWM cycloconverter become open, and protection switching means for turning on and off the unidirectional semiconductor switches of the PWM cycloconverter based on the fault signal output from the fault detection means.