Comparison of pulse-width-modulation control strategies for three-phase inverter systems

A comparison of pulse width modulation (PWM) strategies for three-phase uninterruptible power supplies and motor drive systems based on the total harmonic distortion of the current is presented. The well-known ‘exact’ PWM strategies of harmonic elimination, harmonic minimisation, hysteresis band and space vector modulation are considered as a basis for comparing the equivalent ‘regular sampled’ PWM techniques that have been developed to approximate these exact strategies. Simulation and experimental results are presented to show the differences between the various PWM strategies and to demonstrate the relative harmonic content of each strategy.