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:
Dec. 15, 2009
Filed:
Nov. 21, 2007
Edward Herbert, Canton, CT (US);
Edward Herbert, Canton, CT (US);
Other;
Abstract
This invention teaches power factor corrected 3-phase ac-dc power converters in which the duty-cycles are determined by 'natural modulation', that is, they are forced by a fixed algorithm that has been optimized for efficient switching. The duty-cycles do not regulate the output voltage but they do force the input currents to be proportionately correct for good power factor. A feedback control circuit modulates the effective turns-ratio of a variable dc-dc transformer to regulate the output voltage. For a buck converter, the most efficient duty-cycle is 100%, that is, the buck switch is always on. For a boost converter, the most efficient duty-cycle is 0%, that is, the boost switch is always off. '100% duty-cycle' as defined for a buck 3-phase ac input means that there is no off-time. The switch duty-cycles are as follows: The duty-cycle for the phase with the highest voltage magnitude (the dominant phase) is 100%, and sum of the duty-cycles of the other two phases equals 100%. “0% duty-cycle” as defined for a boost 3-phase ac input means that the input is never short circuited line to line. The duty-cycle for the switch for the phase with the highest voltage magnitude (the dominant phase) is 0%, and switches of the other two phases modulate to control their respective input currents.