Several Modulation Techniques for a Pulsewidth Modulated Inverter

Pulsewidth modulation of a six-step inverter can be accomplished in different ways. Comparisons between different modulation techniques are based primarily on harmonic content in the output waveform and circuit constraints imposed by semiconductor characteristics. Adaptive ratio is a modulation scheme which combines the beneficial features of several available techniques and makes the necessary compromises to optimize the operating characteristics of a modulated six-step inverter.