High frequency PWM technique for two and three level single-phase inverters

A novel pulse width modulation (PWM) technique for high switching frequency two-level and three-level single-phase inverters is presented. The method is based on the same principles as the well-known regular-sampled PWM technique. The novel technique significantly reduces the number of computations required to calculate the switching times by using a modified sampling technique, where the same sample is used over a multiple number of carrier periods. The technique is particularly suited to systems which are limited by sampling rates and control algorithm execution times. Both computer simulation and experimental results are presented to confirm the theory and to demonstrate that the proposed method has no adverse effects and does not significantly increase the harmonic distortion of the voltage and current waveforms.