When the conventional carrier stack modulation method is applied to a dual low-voltage unit hybrid cascade inverter, there is a power imbalance problem between the low voltage units. For this reason, this paper proposes an improved carrier stack modulation strategy. The strategy firstly generates the driving signal of each switch through the traditional mixed carrier stack modulation method, and then obtains the actual driving signal of the switch after power balance optimization of the driving signal of the switch tube. The simulation results show that this strategy can solve the reverse current problem and realize the power balance of the two low-voltage units when the inverter high-voltage unit operates at the fundamental frequency, which makes the output voltage harmonics of the inverter is mainly sideband harmonics centered on mf.
