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. 28, 1995
Filed:
Jan. 13, 1994
Shinichi Kono, Oshino, JP;
Masaaki Fukukura, Oshino, JP;
Fanuc Ltd., Minamitsuru, JP;
Abstract
A slip frequency control method for induction motors, capable of achieving accurate control and excellent in control response. To effect determination of a slip frequency (fs) and an excitation magnetic flux frequency (.omega.0) by software processing to reduce a control error and a control delay caused if hardware elements are employed for the determination of these parameters, a vector control processor divides, in a speed control routine (101-104), the sum of a slip frequency, obtained by dividing the product of a secondary current command (I2) and a proportional constant (K2) by an excitation magnetic flux command (.PHI.), and a remainder (.alpha.') in the preceding routine by a routine executing frequency (CV), so as to derive a slip amount (A) and a remainder (.alpha.) in the present routine. In a current control routine (201 to 205) executed at intervals of a period shorter than that of the speed control routine, the processor divides the sum of the derived slip amount and the remainder (.beta.') in the preceding routine by the number (n) of execution of the current control, to thereby derive slip distribution data (.omega.s) and a remainder (.beta.) in the present current control routine, and further adds data (.omega.r) indicative of an actual motor speed to the derived slip distribution data, to thereby derive an excitation magnetic flux frequency (.omega.0).