Common mode voltage suppression of Vienna rectifiers based on vector modulation
                                                                            WANG Zhi min
（Quanzhou Power Supply Company, State Grid Fujian Electric Power Company, Quanzhou 362000, China）


Abstract: Aiming at the safety and reliability of the Vienna rectifier, the common mode voltage and neutral point imbalance of the Vienna rectifier were studied. A vector modulation was proposed to reduce the common mode voltage and control the voltage balance of the DC side. First of all, the reason of common mode voltage was analyzed. The proposed vector modulation can reduce the common mode voltage. Then the reason of the neutral point balance was analyzed. The proposed vector modulation can realize the neutral point balance control at the same time. Vienna rectifier test bench was used to test the neutral point balance control and common mode voltage suppression effect of Vienna rectifier. The results show that the common mode voltage of the Vienna rectifier can be effectively suppressed, and the line voltage of the Vienna rectifier is a standard five level waveform. The DC side capacitor voltage is effectively controlled and the distortion rate of the input current is effectively controlled.
Key words: Vienna rectifiers; common mode voltage; vector modulation; neutral point voltage balance