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:
Oct. 13, 1992
Filed:
Mar. 08, 1990
Hiromi Inaba, Katsuta, JP;
Kiyoshi Nakamura, Katsuta, JP;
Sadao Hokari, Katsuta, JP;
Yoshio Sakai, Ibaraki, JP;
Naoyuki Outi, Hitachi, JP;
Takeki Ando, Ibaraki, JP;
Satoshi Fukuda, Mito, JP;
Hitachi Ltd., Tokyo, JP;
Hitachi Elevator Engineering and Service Co., Ltd., Tokyo, JP;
Hitachi Engineering Co., Ltd., Ibaraki, JP;
Abstract
A power converter comprising a current-type inverter is disclosed, in which an output of a converter unit is applied as an input to the inverter unit through a DC reactor, and AC power is supplied to a load from the inverter unit. A ripple component of the DC input of the inverter unit is detected, and the switching elements of the inverter unit are controlled by modulation rate if they are to be subjected to PWM control, thus completing a sinusoidal waveform of the output of the inverter unit. Specifically, since the input to the inverter unit is allowed to contain a ripple, the DC reactor is reduced in size. The output of the inverter unit is a sinusoidal AC power containing no high harmonics and therefore the load is free of effects of high harmonics.