Abstract：This paper reveals the power balance principle of the hybrid cascaded multilevel (ML) inverter, which requires that the input average power of each cell must be proportional to the corresponding input voltage. In order to realize power balance, this paper proposes an improved staircase waveform synthesis strategy. After detailed discusses, it points out the prominent advantage of the proposed strategy is no matter how many cells there are cascaded, it can ensure the output power of each cell well balanced in only one output cycle, but it will affect the total harmonics distortion (THD) of the output voltage a little. Finally, this paper gives out the common equations of the proposed power balance strategy for any cascaded cells. Experimental results verify the validity of the proposed strategy.
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2009, Vol. 24 
