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:
Jul. 28, 1981
Filed:
Apr. 24, 1979
John H Cutler, Roanoke, VA (US);
Loren H Walker, Salem, VA (US);
General Electric Company, Salem, VA (US);
Abstract
Disclosed is an AC motor drive system having a variable frequency, variable magnitude AC current supplied from a controlled inverter coupled to a variable DC current source in the form of a converter by way of a DC link including an inductor. The AC motor load is controlled so as to have dual modes of operation in order to optimize torque at any speed which can be produced within the voltage and current limitations of the variable frequency power source. The first mode comprises a constant slip or constant angle mode for operating speeds up to the corner point speed which is defined as the speed at which the motor voltage at full torque matches the maximum voltage the variable frequency inverter coupled thereto can provide. Thereafter, the system enters the second mode by automatically shifting to a constant horsepower variable slip or changing angle mode for operating speeds beyond the corner point speed.