US 11,990,849 B2
Hybrid multi-level inverter
Jih-Sheng Lai, Blacksburg, VA (US); and Moonhyun Lee, Torrance, CA (US)
Assigned to Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US)
Filed by Virginia Tech Intellectual Properties, Inc., Blacksburg, VA (US)
Filed on Jan. 28, 2022, as Appl. No. 17/587,405.
Claims priority of provisional application 63/143,718, filed on Jan. 29, 2021.
Prior Publication US 2022/0247326 A1, Aug. 4, 2022
Int. Cl. H02M 7/483 (2007.01); H02M 1/00 (2006.01); H02M 3/335 (2006.01); H02M 5/453 (2006.01); H02M 5/458 (2006.01); H02M 7/49 (2007.01); H02M 7/5387 (2007.01)
CPC H02M 7/4835 (2021.05) [H02M 1/0095 (2021.05); H02M 3/33573 (2021.05); H02M 7/53871 (2013.01); H02M 5/453 (2013.01); H02M 5/458 (2013.01); H02M 5/4585 (2013.01); H02M 7/483 (2013.01); H02M 7/49 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A multi-level inverter, comprising:
n H-bridge cells, each H-bridge cell of the n H-bridge cells configured to selectively provide at its output terminals one of: a zero voltage, a positive polarity of a voltage at its input terminals, and a negative polarity of the voltage at its input terminals, wherein the corresponding input terminals of each H-bridge cell of the n H-bridge cells is configured to be coupled to one of n DC voltage sources, wherein at least two of the n DC voltage sources have different voltage magnitudes;
m H-bridge cells, each H-bridge cell of the m H-bridge cells having a capacitor coupled in parallel with its input terminal, the each H-bridge cell of the m H-bridge cells configured to selectively provide one of: charging the capacitor from its output terminals, discharging the capacitor to its output terminals, and providing zero voltage at its output terminals, wherein the n H-bridge cells and the m H-bridge cells are connected in a cascade formation such that a voltage output of the multi-level inverter is equal to at least a sum of output voltages of the n H-bridge cells and the m H-bridge cells; and
a controller coupled with the n H-bridge cells and the m H-bridge cells configured to:
determine a first half-cycle period and a second subsequent half-cycle period of a same duration as the first half-cycle period, each of the first half-cycle period and the second half-cycle period including a set of switching instances, wherein each switching instance in the set of switching instances is determined at least in part based upon the voltage magnitudes of each of the n DC voltage sources, and
selectively control the n H-bridge cells and the m H-bridge cells at each switching instance of the set of switching instances of the first half-cycle period to generate a step-wise increasing followed by a step-wise decreasing voltage output of the multi-level inverter and selectively control the n H-bridge cells and the m H-bridge cells at each switching instance of the set of switching instances of the second half-cycle period to generate a step-wise decreasing followed by a step-wise increasing voltage output of the multi-level inverter.