Linear quadratic optimal control of a single-phase grid-connected inverter with an LCL filter

A linear quadratic optimal control strategy for a single-phase grid-connected inverter with LCL filter is presented in this paper. Firstly, the mathematical model of the grid-connected inverter is investigated. Then, its linearized small signal state-space model is obtained, and a linear quadratic regulator (LQR) is achieved by the solution of algebraic Riccati equation (ARE). Finally, some simulations have been done on the MATLAB/Simulink platform in detail, which verifies the excellent performance of the proposed approach in steady-state and transient operation conditions.