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. 05, 1993
Filed:
Jun. 02, 1988
Tokunosuke Tanamachi, Katsuta, JP;
Kiyoshi Nakamura, Katsuta, JP;
Kiyoshi Nakata, Ibaraki, JP;
Yoshio Tsutsui, Katsuta, JP;
Wataru Miyake, Katsuta, JP;
Katsuaki Suzuki, Kitaibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an inverter control apparatus including a pulse width modulation inverter supplied with power from a d.c. power source to generate an a.c. output, a frequency control unit controlling the output frequency of the inverter, and a voltage control unit controlling the output voltage of the inverter, a frequency adjusting unit is provided to adjust the operating frequency of the inverter so that the product of voltage and time in each positive half cycle of the output voltage of the inverter becomes equal to that in the next adjacent negative half cycle of the output voltage of the inverter. When the inverter is used in an apparatus for controlling an induction motor, the frequency adjusting unit adjusts the output frequency of the inverter according to the result of detection of a ripple factor of an input voltage of the inverter, and a frequency adjusting-factor correcting unit corrects the frequency adjusting factor of the frequency adjusting unit according to at least one of the output of an induction-motor rotation frequency detector and the output of the voltage control unit.