Design of a single-phase grid-connected photovoltaic system based on deadbeat current control with LCL filter

The utilization of voltage source inverter (VSI) connected to the grid in photovoltaic systems requires application of control systems capable of regulating the active and reactive output current, ensuring high power quality levels and achieving relative immunity to grid perturbations. In the single phase system the LCL filter is adopted, which can reduce the required filtered inductance and the cost. However, the performance of the power flow depends largely on the quality of the applied current control strategy. In this paper an optimized control scheme for the VSI is proposed to improve the current regulation capability based on the digital deadbeat control using a minimum number of sensors. Detailed discussions about the design of the controller are given out. Finally simulation and experimental results verify the correctness of the analysis and availability of the control strategy.