Electrical transmission or interconnection systems – Plural supply circuits or sources – One source floats across or compensates for other source
Reexamination Certificate
2004-07-07
2008-07-29
Sherry, Michael J (Department: 2836)
Electrical transmission or interconnection systems
Plural supply circuits or sources
One source floats across or compensates for other source
C327S163000
Reexamination Certificate
active
07405494
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.
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Anderson Jason S.
Pfitzer Hans-Erik
Tassitino, Jr. Frederick
Westerfield Michael
Cavallari Daniel
Eaton Corporation
Myers Bigel & Sibley & Sajovec
Sherry Michael J
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