Non-sinusoidal modulating functions for three-phase inverters

A major class of PWM techniques for power inverters is distinguished by the use of some specified modulating functions. The characteristics of the inverters can be improved considerably by using certain nonsinusoidal modulating functions in place of the usual sinusoid. 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 for the so called incremental PWM method, but the idea can be extended to a broad class of PWM techniques.