A Fast Space-Vector Algorithm for Multilevel Converters without Coordinates Transformation

In recent years, Multilevel Converters has become a promising technology for medium voltage applications. Nevertheless, when the number of levels increases, switching states selection becomes a hard task. The main concerns are with computational effort for digital implementation and capacitor voltage balance. Improvements in Pulse Width Modulation (PWM) strategies has been achieved thanks to researches contributions. This paper proposes a modification in the algorithm introduced by Celanovic and Boroyevich. In the new algorithm the coordinates transformation is not necessary, which reduces the computational effort. General concepts of PWM for multilevel converters are presented and, the new algorithm is presented and compared with the previous. Simulation based results are exploit to show that the algorithm is so effective as the previous solution. Experimental results illustrates a DSP control solution for an inverter up to 7-level.