Elimination of low-frequency harmonics caused by PWM in a three-phase soft-switched boost rectifier

This paper presents three major causes of low-frequency harmonics in a high-frequency soft-switched three-phase PWM boost rectifier: pulse width limits; an improper space vector modulation scheme; and dead time. Among these, the pulse width limits are related to soft-switching techniques. To eliminate undesirable low-frequency harmonics, each cause is illustrated and a solution is provided. Both simulation and experimental results prove the effectiveness of the proposed solutions. Due to the similarities between boost rectifiers and voltage source inverters, the conclusions of this paper are also applicable to high-frequency PWM voltage source inverters