Analysis of random PWM switching methods for three-level power inverters

This paper presents a generalized theory which covers both two-level and th ree-level random pulsewidth modulation (RPWM) schemes, Various three-level RPWM schemes with low switching frequency are presented and compared with t wo-level schemes. Three-level RPWM schemes have less discrete harmonics and continuous noise than two-level RPWM schemes. They have desirable spectral characteristics and can be employed in high-voltage inverter-fed motor dri ves, Measurements have confirmed the theory and the attractive features of three-level RPWM schemes.