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:
Jan. 09, 1996
Filed:
Jul. 30, 1993
Yu Qin, Troy, MI (US);
Shanshan Du, Troy, MI (US);
Controlled Power Company, Troy, MI (US);
Abstract
A UPS having a ferroresonant transformer is selectively switched from AC line voltage to an inverter by a control method and apparatus using fuzzy logic to select an optimum switching point. The control apparatus and method senses output load current, output voltage and input voltage. Output current is used to calculate output load as a percentage of full load. First membership functions relating to percent load, second membership functions relating to output voltage, third membership functions relating to input voltage switching points, and rules using percent load membership and output voltage membership as antecedents and values of input voltage switching points as consquents as determined by regulation characteristics of the ferroresonant transformer, are used to execute a fuzzy inference and generate dynamic input voltage switching points for comparison with line input voltage to control switching of the UPS between line and inverter sources.