Model Predictive Control of Current with Fixed Switching Frequency on VEINNA Rectifier

The model predictive control of current on finite control set (FCS-MPCC) on VIENNA rectifier can only output a single discrete voltage vector in one control cycle. The switching frequency is variable, and the quality of the input current depends on the higher sampling frequency. To solve these problems, a model predictive control of current with fixed switching frequency (FSF-MPCC) is proposed. Firstly, the reference voltage vector and its sector are calculated by the prediction model. Then the optimal voltage vector is predicted by the objective function and the finite set model. And then, three voltage vectors are determined by combining the optimal voltage vector and the two basic vectors of the sector. Finally, the SVPWM algorithm is used to convert the three voltage vectors into the corresponding switching signals to realize the fixed switching frequency control. And it can reduce the switching frequency and make the filter parameter design convenient. Meanwhile, the FSF-MPCC method can track the reference voltage vector more accurately and reduce the THD of the input current. The simulation results has showed that the proposed method is feasible and effective.