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. 29, 2008
Filed:
Jul. 07, 2004
Frederick Tassitino, Jr., Wake Forest, NC (US);
Hans-erik Pfitzer, Wake Forest, NC (US);
Jason S. Anderson, Raleigh, NC (US);
Michael Westerfield, Durham, NC (US);
Frederick Tassitino, Jr., Wake Forest, NC (US);
Hans-Erik Pfitzer, Wake Forest, NC (US);
Jason S. Anderson, Raleigh, NC (US);
Michael Westerfield, Durham, NC (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
Paralleled uninterruptible power supplies (UPSs) including respective pulse-width modulation (PWM) power converter circuits coupled in common to an AC load bus have PWM cycles that are synchronized. In particular, sampling of control inputs of the PWM power converter circuits may be synchronized, such that, for example, sampling of control inputs to the PWM power converter circuits occurs at substantially the same time for each of the PWM power converter circuits. A common phase reference corresponding to an AC voltage phase for the AC load bus may be provided, and the PWM cycles of each of the power converter circuits may synchronized, e.g., phase locked, to the common phase reference. More particularly, the respective PWM cycles of the UPSs may be phase locked to phase locked sinusoidal reference signals generated at each of the UPSs. Sampling for other control functions may also be synchronized to the PWM cycles.