Controller Decoupling Design of LCL Three - Phase Grid - Connection Inverter Based on Capacitor Voltage Feedforward

Under the same filtering effect, the total inductance required by the LCL filter is smaller than that of the L filter, and is more suitable for the application of the high-power grid connected devices. In this paper, a model of dq synchronous rotating coordinate system is established for the structure of LCL filter, and the two axes of dq are controlled by decoupling. The design method of the double closed loop controller with capacitive voltage and grid connected current is studied, which improves the control precision and obtains a certain system robustness. The simulation results show that the design method of decoupling controller design can make the inverter run steadily and obtain high quality grid connected current.