Space-vector pulse-width modulation algorithm for multilevel voltage source inverters based on matrix transformation and including operation in the overmodulation region

Abstract

Multilevel voltage source inverters are most promising when employed in high-power and high-voltage applications. As the number of inverter levels increases, the algorithm of space-vector pulse-width modulation (SVPWM) becomes increasingly complex. Based on the intrinsic relationship between SVPWM algorithms for 2-level inverters and those for arbitrary-level inverters, here a novel SVPWM algorithm is proposed for an arbitrary-level inverter. Considering that the nearest three vectors are used to synthesise the reference vector, the on-time of the voltage vector for an arbitrary-level inverter can be acquired from that for a 2-level inverter via the use of a linear transformation. This algorithm is verified through simulation and experiments, with the latter proving that the proposed algorithm can meet the real-time requirements of multilevel inverters.