An algorithmic approach to space vector modulation for multiphase inverters

Since late 1990s multiphase drives have become a serious alternative to three-phase drives in some particular applications such as electric ship propulsion, locomotive traction, electric vehicles and high power industrial applications. Nowadays the research activity is focused on the development of control strategies that can exploit the degrees of freedom that exist in multiphase machines. As known, a multiphase motor cannot be analyzed using the space vector representation in a single d-q plane, but it is necessary to introduce multiple d-q planes. In this paper the problem of the space vector modulation of multiphase inverters with an odd number of phases is solved introducing the concepts of reciprocal vector and adopting an algorithmic approach, i.e. the information on the inverter configurations, saved in a look-up table, is accessed on the basis of an iterative procedure. The proposed approach, confirmed by experimental tests, allows the full exploitation of the dc input voltage and the simultaneous modulation of voltage space vectors in different d-q planes.