The neutral point-potential and current model predictive control method for Vienna rectifier

A three-phase three-level Vienna rectifier has been widely used in the front-end PFC modules of electric vehicle and data center DC power supply system with the advantages of without dead-time, low switch voltage stress and small grid current harmonic. However, to achieve unity power factor and alleviate specific harmonic pollution, its controller design becomes more complex. Therefore, a novel finite control set model predictive control strategy is presented. The behavior of the output voltage is firstly predicted for each possible switching state in each sampling interval based on the model of a Vienna rectifier. Besides, the midpoint voltage imbalance and time delay caused by the calculation may deteriorate the grid current or even damage the device seriously. Thus, a cost function is first built to balance the neutral-point-potential voltage. After then, the cost function is updated by considering the delay caused by the calculation, sampling and gate driver. Compared with the conventional PI-SVM control strategy, the effectiveness of the proposed model predictive control strategy is validated by both the simulation and experimental results.