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:
Apr. 09, 1985
Filed:
Mar. 01, 1984
Tadashi Ashikaga, Tokyo, JP;
Masayuki Terashima, Sakura, JP;
Kabushiki Kaisha Meidensha, , JP;
Abstract
In a vector control method and system for an induction motor, the decoupling calculation and 2-3 phase transformation are combined to simplify the system configuration, and the plus and minus signs of trigonometric signals are changed according to the rotational direction to enable four-quadrant operation. Further, in the case of a 3-phase induction motor driven by a PWM inverter, the number of the triangular (carrier) wave signals generated during one period of the power supply signal is increased with decreasing frequency of the supply voltage signal to improve the response characteristics when the motor is rotating at a low speed. Furthermore, an initial supply voltage signal with a predetermined frequency is applied to the triangular wave signal generator, when the motor stops, to generate an initial secondary magnetic flux before starting the motor.