US 9,812,900 B2
Switching systems and methods for use in uninterruptible power supplies
James Patrick Richardson, Bellingham, WA (US); and Thanh Quoc Le, Ferndale, WA (US)
Filed by Alpha Technologies Inc., Bellingham, WA (US)
Filed on May 7, 2015, as Appl. No. 14/706,779.
Application 14/706,779 is a continuation of application No. 13/352,308, filed on Jan. 17, 2012, granted, now 9,030,045.
Claims priority of provisional application 61/435,317, filed on Jan. 23, 2011.
Prior Publication US 2015/0244211 A1, Aug. 27, 2015
This patent is subject to a terminal disclaimer.
Int. Cl. H02J 7/00 (2006.01); H02J 9/06 (2006.01); H02M 1/10 (2006.01); H02M 1/00 (2006.01)
CPC H02J 9/062 (2013.01) [H02J 9/06 (2013.01); H02M 1/10 (2013.01); H02J 2009/067 (2013.01); H02M 2001/0035 (2013.01); Y02B 70/16 (2013.01); Y10T 307/615 (2015.04)] 12 Claims
OG exemplary drawing
 
1. An uninterruptible power supply for providing an output power signal to a load comprising:
a ferroresonant transformer;
a resonant capacitor operatively connected to the ferroresonant transformer; and
an inverter operatively connected to the ferroresonant transformer, wherein:
the inverter is configured to generate the output power signal based on at least one inverter control signal such that the output power signal is a quasi square wave having a first change of phase, an upper limit, and a second change of phase; and
the at least one inverter control signal is
pulse-width modulated between the first change of phase and the upper limit,
pulse-width modulated between the upper limit and the second change of phase,
held in an ON state when the output power signal is at the upper limit.