Deadbeat Predictive Control Strategy Based on UDE for Dual-Buck Grid-Connected Inverter

In this paper, an uncertainty and disturbance estimator (UDE) method is proposed for dual-buck grid-connected inverter to improve the robustness of deadbeat predictive current control with respect to the variation of model parameters. Although deadbeat control has fast dynamic response, it has the delay problem in digital control and relies on accurate model parameters. Therefore, a two-step prediction method is adopted to compensate the digital control delay. Then, the prediction current error caused by parameters mismatch is analyzed. Based on the idea of regarding the variation of model parameters as an uncertain disturbance to the PV system, the deadbeat predictive control strategy based on UDE is proposed to reduce the sensitivity to parameters. Comparative simulation results verify that the proposed control method can effectively improve the tracking ability of the grid-connected current to the reference value when the system parameters change.