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:
Jul. 02, 1996
Filed:
Apr. 21, 1995
Ryoso Masaki, Hitachi, JP;
Nobuyoshi Mutoh, Hitachinaka, JP;
Hitachi, Ltd., , JP;
Abstract
The invention provides a control apparatus for an induction motor to maintain torque following controllability even with use of inexpensive speed detection units having detection delay. In a control unit, a phase correction arithmetic circuit uses a motor speed detection value detected by a speed sensor and a low-pass filter and a detection delay time of a control system to compute a correction phase. An adder adds the correction phase to a magnetic flux phase obtained by a vector control computation. The addition corrects a magnetic flux phase deviation due to detection delay of the correction phase of a primary current command, and compensates for the detection delay so as to maintain the torque following controllability of an inductor motor.