Advanced current control based on linear quadratic regulators for 3-phase grid-connected inverters

This paper proposes an optimal current control with linear quadratic regulators for 3-phase grid-connected inverters. Because the 3-phase current control is a multivariable control problem with multiple interconnected loops, the traditional control methods, like proportional-integral-derivative control and predictive control, have the difficulty in optimizing their parameters. The proposed control algorithm, however, uses the linear quadratic regulator technique to synthesize the state feedback gains and achieve optimal performance. This paper also introduces the disturbance decoupling strategy to eliminate the impact of the disturbance of grid voltage variation. The system modeling and control design procedure are discussed in the paper. And simulation and experimental results are presented in the paper to verify the effectiveness of the proposed current control algorithm.