DSP-based simplified space-vector PWM for a three-level VSI

Multilevel inverters have gained attention in high power applications due to numerous advantages in comparison with the conventional two-level inverter. During recent decades most of the research about the multilevel inverters has been focused on the analysis of the Pulse Width Modulation (PWM) techniques used to control the power semiconductors. In this paper a simplified Space-Vector Modulation (SVM) algorithm for a three-level Neutral-Point Clamped (NPC) inverter is implemented on a Freescale^® DSP56F8037. The algorithm is based on a simplification of the space-vector diagram of a three-level inverter into a two-level inverter. Once the simplification has been achieved calculation of dwelling times and switching sequences are carried out in the same way as for a two-level SVM method. Experimental results validate the simplified algorithm.