A general SVM strategy for n-level m-phase converter based on voltage level

Multilevel inverters are increasingly becoming an excellent substitution of conventional two-level inverters owing to their superior capability, especially in high-power medium voltage applications. In both types, SVM (Space Vector Modulation) is mostly employed due to its superiority. However the complexity of normal SVM increases sharply with the increased number of level and/or phase of inverters. Consequently the feasibility for SVM applying in situation more than 5 levels and/or more than 3 phases becomes highly restricted. This paper proposes a general SVM strategy based on voltage level (LSVM) for n-level m-phase converters. Different from the conventional SVM based on voltage vector, LSVM focuses on voltage level possesses the combination of universality and simplicity without relying on increasing level and phase. Physical meaning and algorithm theory directly orienting voltage level are briefly discussed. On the basis of presentation of LSVM method, several key problems are discussed, such as level decomposition of integer and decimal parts, on-times calculation, switch state selection, new dead zone of multilevel system, zero-order component compensation. Finally, unification of LSVM and conventional SVM is introduced, which indicates that SVM is just an alteration type with special physical meaning for the generalized LSVM model. Simulation on a 3 phases and 5 levels system verify its feasibility and simplicity.