A simple control arithmetic of step wave cascaded multilevel inverter with different voltage step

Besides effectively reducing the voltage stress of switches, the cascaded multilevel inverter could also improve the quality of output waveforms by addition of waveforms. The step waveform addition is a usual method. The addition could reduce the loss of switches, but the introduced angle of flow calculating methods of cascade inverters based on step waveform addition are only suitable for cascaded inverters with the same voltage step. To this situation, an angle of flow calculating method of inverters with the different voltage step is proposed in this paper. The method is very suitable for the application of solar battery cascaded inverters and fuel battery cascaded inverters. The method follows the equal area principle, and the online calculation is realized by some constraint conditions. Finally, the correctness of the method is validated by simulations.