Aiming at the problem of voltage drop at the common coupling point (PCC) caused by load change in the low-voltage distribution network, this paper analyzes the principle of voltage drop by establishing the grid connection model of renewable energy through a grid-connected converter. Then, combined with the characteristics of a high impedance ratio (Rl/Xl) in the low-voltage distribution network, the influence of load active power and reactive power on the voltage at the PCC is analyzed. The emphasis of this paper is to propose an improved model predictive power control (MPPC) strategy to realize the voltage support at PCC without static difference. In the process of designing the controller, the voltage support at the PCC is taken as the target, the power is taken as the control object, and the cost function of the MPPC is selected. The capacity of the converter is used as the constraint condition for voltage support. Finally, the correctness and effectiveness of the proposed converter control method are verified by Matlab/Simulink simulation.