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:
Jun. 09, 1987
Filed:
Jun. 18, 1985
Alberto Abbondanti, Penn Hills Township, Allegheny County, PA (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
In an induction motor drive a signal representative of the torque T as derived by sensing only the stator armature current I, and the slip frequency f.sub.2 and by calculating instantaneously T=I.sub.1.sup.2 F, where F is a function of f.sub.2 /R.sub.2, where R.sub.2 is the rotor resistance of the motor. The value of R.sub.2 is adjusted to match temperature by generally two alternative methods: (1) measuring the stator temperature, relying on the change of resistance R.sub.1, known experimentally, and applying an equivalent change for the rotor resistance R.sub.2 ; (2) by running the motor at rated speed and determining experimentally R.sub.2 /f.sub.2 as a function of F.