A generalized modulation technique for multilevel converters

In the paper a mathematical model of multilevel PWM-rectifiers is pointed out. The model formulation is generalized to "m" voltage levels and is unified for neutral-point-clamped, cascaded-H-bridge, and flying-capacitors topologies. A modulation technique is described for active front-ends. Specific solutions are proposed for the different regions of the complex plane correspondent to the m-levell structure of the converter. Instead of complex look-up tables, very simple relations are given in order to identify the region and to select the most effective modulation pattern. Some opportunities to conveniently use the intrinsic redundancy of the converter topology are described.