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. 24, 1984
Filed:
Nov. 25, 1981
Applicant:
Inventor:
William P Curtiss, Winthrop, MA (US);
Assignee:
The Charles Stark Draper Laboratory, Inc., Cambridge, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318798 ; 318806 ; 318807 ; 3241 / ;
Abstract
Flux saturation in a current-excited induction motor is detected by sensing an accompanying increase in the level of the third harmonic in the waveform of the voltage across the stator windings. The level of the third harmonic relative to a fixed reference represents flux error. Nulling the flux error with a servo loop facilitates torque control by maintaining constant flux.