A neutral point potential balance control strategy based on vector controlled VIENNA rectifier

The neutral point potential is an important problem when designing three-phase/level/switch VIENNA rectifier. The imbalance of neutral point potential not only increases voltage stresses of power device, but also results in harmonic distortion of input current waveform. This paper, by setting up neutral point potential model, detail reasons of neutral point imbalance are analyzed, then a method based on balanced factor calculation was proposed, by real-time calculation, the duty cycle of PWM signal can be generated. This proposed control strategy balanced the neutral point potential well. Last, the simulation and vector controlled experiment results verified the feasibility of the proposed method.