Microsoft Word - ALL_15-TIE-2235

Several pulsewidth modulation (PWM) strategies have been proposed for three-phase multilevel converters. Typically, these PWM methods can be either space-vector or carrier-based implemented, where the carrier-based implementation usually presents a lower computation complexity. In this paper, a novel approach for the carrierbased implementation of different existing PWM methods is proposed for threeand four-level dc-ac converters, which can be easily extended to any number of levels. The main features of the proposed approach are its reduced computation complexity and computation time. On the other hand, the proposed approach suggests the derivation of novel PWM strategies which can potentially present improved performance features. As an example, two new discontinuous PWM (DPWM) strategies are proposed for the four-level converter. One of these DPWM strategies presents lower weighted total harmonic distortion than other previously proposed strategies. Simulation and experimental results verify the effectiveness of the proposed approach and novel DPWM strategies.