Abstract：In order to enhance the convergent speed, a method based on equality of area and superposition of barycenter of the PWM section with the sine-reference signal for obtaining initial values is proposed. The SHEPWM non-linear equations of five-level voltage inverters for full range modulation index M are solved and at least one group of solutions is obtained for each M with a step of 0.01. Solving process of the equations proved that the initial values are very effective. The numbers of switching angle between different output levels vary with M values. Based on PSIM6 software and a five-level cascade inverter prototype, two solutions for M equal to 0.5 are investigated by simulation and experiment. The result proved the conclusions reached.
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2009, Vol. 24 
