A Unified Carrier-Based Pulsewidth Modulation for Three-Phase Vienna-Type Rectifiers

Compared with space-vector pulsewidth modulation (SV-PWM) schemes, carrier-based PWM (CB-PWM) schemes feature less digital calculation burden. Unfortunately, since different CB-PWM schemes were not represented by a unified expression and the relationship between the injected zero-sequence components (ZSCs) and the switching-state sequences is not revealed, the CB-PWM has poor flexibility in designing the switching-state sequences. In this article, a unified carrier-based PWM (UCB-PWM) is proposed to unify the expressions of different CB-PWM schemes. The ZSC of the proposed UCB-PWM is classified into a basic ZSC (B-ZSC) and a redundant ZSC (R-ZSC). The B-ZSC is a shared component of all CB-PWM schemes, and the dwelling time of redundant small vectors can be distributed by injecting different R-ZSCs. Also, the neutral-point voltage balance control based on either continuous PWM or discontinuous PWM (DPWM) can be achieved by injecting R-ZSCs. Besides, not only the existing carrier-based DPWM schemes but also new carrier-based DPWM schemes are derived by the proposed UCB-PWM. Finally, experimental results verify the correctness and advantages of the proposed UCB-PWM.