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. 18, 2000
Filed:
Apr. 12, 1996
Alan P French, Florissant, MO (US);
Emerson Electric Motor Co., St. Louis, MO (US);
Abstract
A method for controlling the average voltage applied to a phase winding of a reluctance machine during periods of current increase, stable current control, and current decrease to improve machine efficiency and thereby reduce acoustical noise produced by the machine and unwanted vibration. According to one aspect, a method is provided whereby a maximum duty cycle is selected and voltage is applied to the phase winding during the period of current increase according to the maximum duty cycle until the current reaches a desired peak current value and thereafter the voltage applied to the phase winding is equal to the lesser of the voltage required to keep the phase current at the predetermined peak current value or the voltage corresponding to the maximum duty cycle.