New fast space-vector modulation for multilevel converters based on geometrical considerations

Abstract

This paper presents an fast and simple modulation algorithm for voltage source multilevel converters for calculating the switching times and the space vectors using simple geometrical considerations. This method provides an online computation of the nearest switching vectors sequence to the reference vector and the on-state durations of the respective switching state vectors without trigonometric function calculations, look-up tables or coordinate system transformations which increases the computational load corresponding to the modulation of multilevel converter. The low computational cost of the proposed method is always the same and it is independent of the number of levels of the converter.