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:
May. 25, 1993
Filed:
May. 28, 1991
Applicant:
Inventor:
Michika Uesugi, Fuji, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318803 ; 318805 ;
Abstract
A d.c. input current to a variable-voltage, variable-frequency inverter is detected, the inverter variable-speed driving a compressor which has a load torque changing with the rotary position and driven by an induction motor. The detected d.c. input current is sampled in synchronization with the timing, when the inductive load components of a current flowing through the induction motor become null. The sampled current value is output as a slip signal of the induction motor. A compensated d.c. voltage command is derived from the slip signal, and the input voltage to the inverter is regulated in acccrdance with the compensated d.c. voltage command.