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A model predictive current control scheme with dc-link capacitor voltages fluctuation suppression for the four-switch three-phase rectifier (FSTPR) in balanced grids is presented. The proposed control scheme is a type of the finite-control-set model predictive control scheme and is based on the discrete-time model of the system. From this model, the values of input currents and dc-link capacitor voltages are predicted for all switching states of the FSTPR. On the basis of a predefined cost function, the switching state, which minimises the errors between input currents and their references as well as the difference between two dc-link capacitor voltages at the next sampling instant, is selected. Simulation results are presented to confirm the effectiveness of the proposed control scheme.

This paper presents a model predictive current control(MPCC) strategy for single-phase voltage source PWM rectifiers with constant switching frequency using the modulated method. In order to minimize d-axis and q-axis current errors over a time horizon, the instantaneous variation rates of d-axis and q-axis currents are discussed to predict d-axis and q-axis currents at the next sampling point. The impact of coupling inductance error in the MPCC is analyzed. The inductance error will cause an obvious effect on the reactive power, and have no effect the active power in the adopted MPCC scheme. Comparing with the conventional PI-based instantaneous current control (PI-ICC) approach, the proposed method remains an inherent rapid dynamic response as a result of MPC controller, and also achieves zero steady-state current errors. Experimental results have been conducted to demonstrate the effectiveness of the proposed algorithm and the correctness of the sensitivity analysis to the grid-side inductance error.