An optimized PWM modulation scheme for high power three-level converter

The additional switching loss and the narrow pulses will not only decrease the efficiency of the high power converter, but also shorten the lifetime of the power switches. An optimized three-level SVPWM Modulation scheme is proposed in this paper. In which, the vector space is re-divided first. Then the suitable switch sequence is selected to realize a smooth transition and reduce the additional switching loss when reference vector rotates from one region to another. At the same time, the generation of narrow pulses can also be avoided in a large scale. And a good harmonic characteristic can be obtained. The simulation and experiment results verify the validity of the proposed modulation scheme.