Nonsinusoidal modulating functions for three-phase inverters

A major class of pulse-width-modulation (PWM) techniques for power inverters is distinguished by the use of reference, or modulating, functions. The characteristics of these techniques can be improved considerably by employing nonsinusoidal modulating functions in place of the usual sinusoidal function. Two kinds of modulating functions are considered, and their impact on the inverter performance is analyzed. Both of them result in a significantly increased fundamental and reduced harmonic content of the inverter output voltage. Implementation of the optimal nonsinusoidal modulating functions is illustrated by their application in the incremental PWM method, but the idea can be extended in a broad class of other PWM techniques