Abstract：Compared with the quarter-symmetry SHEPWM method of multilevel inverters, half-cycle symmetry SHEPWM method has infinite solutions. Compared with asymmetry SHEPWM method, half-cycle symmetry SHEPWM equations need less computations and data storage space. Therefore the half-cycle symmetry SHEPWM method is more attractive. Take a five-level inverter as an example, with a case of 20 switching points in half-cycle and M=0.75, this paper studies in detail the formulation and solutions of half-cycle symmetry multilevel SHEPWM problems. Simulations based on PSIM 6 package are carried out. A five-level cascade inverter prototype is constructed and experimentally investigated based on the same solutions used in the simulations. Experimental results agree well with the simulations, and prove the validity and practicability of the proposed method.
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2010, Vol. 25 
