An Improved Power Compensation based-on Model-free Predictive Power Control of Vienna Rectifiers Under Distorted Power Grid

Vienna rectifiers are widely used in charging piles and aerospace DC power supply systems. The traditional control method can guarantee the stable operation of the system only under ideal condition. The control performance of the system will be destroyed by the non-ideal grid and the inaccurate filter inductance parameter in the controller. In this paper, an improved model-free predictive current control (MFPCC) strategy is adopted, and the idea of ultra-local model and current difference is combined to improve the parameter robustness. The dependence of traditional model predictive current control (MPCC) method on inductance parameters has been avoided. Aiming at solving the problems of excessive input grid current harmonics and double-frequency ripples of active/reactive power in the case of unbalanced and distorted grids, this paper adopts an improved power compensation method. Different control objectives have been achieved by employing different power compensation values. The control objectives include keeping the grid current sinusoidal and eliminating the double-frequency ripples of active or reactive power. Eliminating double-frequency ripples of active or reactive power at the cost of unbalance of grid current, but the current is always sinusoidal. Finally, the feasibility of the proposed method is verified by experimental results.