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:
Nov. 03, 1992
Filed:
Dec. 10, 1990
Tetsuaki Nagano, Aichi, JP;
Mitsubishi Denki K.K., Tokyo, JP;
Abstract
An induction motor controller which compensates for changes in primary resistance values and secondary resistance values that occur with changes in temperature. Multi-phase current and voltage values are detected at the motor input and converted into primary currents and voltages within an orthogonal system and are used to calculate equivalent and estimated equivalent values of magnetic flux. The flux values are used to generate an estimated value of rotary angular velocity of the induction motor, which is used as a basis for controlling in a feedback manner the generation of the command signals for the motor. The magnetic flux values generated in response to the orthogonal voltage and current values are sensitive to a predetermined primary resistance value and a predetermined secondary resistance value. Circuits for automatically changing the predetermined primary resistance value alone or together with the predetermined secondary resistance value, in response to ones of the flux values, are provided. As a result of compensation for the change in the predetermined resistance values as a function of temperature, accurate control of the angular velocity of the motor can be obtained.