A hybrid carrier-based discontinuous PWM with neutral-point voltage ripple and current distortion reduction for Vienna rectifier

The three-level Vienna rectifier is widely used in industrial applications, such as electric vehicle charging systems and telecommunication power systems. Discontinuous pulse width modulation (DPWM) is widely used in three-level AC/DC converters due to its features of switching loss minimization. However, the problems of neutral-point voltage ripple, current zero-crossing distortion, and switching losses are mutually coupled for the Vienna rectifier. To address these issues, a hybrid carrier-based discontinuous pulse width modulation (HCB-DPWM) with reduced neutral-point (NP) voltage ripple and current distortion is proposed. First, the pi$$ \pi $$/6 clamping period of the conventional DPWM is divided into three-type clamping intervals, which reduce NP voltage ripple with shortened clamping period. Then, the elimination of current distortion around the current zero-crossing point and the switching loss reduction are investigated. The implementation of the proposed HCB-DPWM is given in detail. Finally, the simulation and experimental results of the Vienna rectifier are presented to validate the performance that the proposed HCB-DPWM can eliminate current zero-crossing distortion and reduce neutral-point voltage ripple with different modulation indices. This paper proposed a hybrid carrier-based DPWM method for three-level Vienna rectifier to suppress the NP voltage ripple and reduce current distortion simultaneously. First, by analyzing the effects of vectors and switching states on the neutral-point voltage, the clamping modes are divided into three-type clamping intervals to suppress NP voltage ripple. Then, the phase reference voltages are clamped to zero near the current zero-crossing point to eliminate current zero-crossing distortion. Finally, the phase with maximum current is clamped in the peak clamping region to optimize switching loss. image