Maximal voltage three-phase PWM without third harmonic injection

摘要

An inverter control circuit includes means for continuously computing and subtracting an average voltage from each of three modulating input waveforms. The average voltage is computed by determining the instantaneous maximum and minimum voltages of the three waveforms, summing these voltages, and then dividing them by an averaging factor. The shifted modulating waveforms are then compared with a high- frequency carrier wave to modulate the duty cycles of the inverter outputs to approximate desired output waveform characteristics.