CPC H02M 1/15 (2013.01) [H02M 5/293 (2013.01); H02M 7/53 (2013.01); H02M 1/0054 (2021.05); H02M 1/0074 (2021.05); H02M 1/0095 (2021.05); H02M 3/33571 (2021.05); H02M 7/4833 (2021.05)] | 19 Claims |
1. A stacked half-bridge AC-AC converter comprising:
a first half bridge including a first switching device and a second switching device, wherein a junction point of the first and second switching devices is coupled to a first AC output terminal of the converter;
a second half bridge including a third switching device and a fourth switching device, wherein a junction point of the third and fourth switching devices is coupled to a second AC output terminal of the converter and wherein the first and second half bridges are connected in a ladder configuration across an AC input of the converter;
first and second input capacitors connected in a ladder configuration across the AC input of the converter, wherein a junction point of the first and second capacitors is connected to a junction point of the first and second half bridges forming a neutral point of the converter; and
a controller configured to operate the switching devices according to a plurality of switching sequences, each switching sequence including one or more switching patterns, and each switching pattern including a plurality of switching states, each switching state including pulse width modulated operation of at least one switching device from each of the first and second half bridges, wherein:
at least one of the plurality of switching sequences includes one or more patterns of switching states selected to inject current into the neutral point to regulate a voltage of the neutral point, reduce switching losses, or equalize losses among the switching devices.
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