Design and Comparison of Optimization Control Strategy for three-phase Shunt APF

To make the control strategy design concise and easy to practical application. Based on a linear three-phase shunt Active Power Filter (APF) model, the Linear Quadratic Regulator (LQR) is utilized to obtain the optimal state feedback control rate. To improve the stable performance of the system, the optimal state feedback control combines with an output integral feedback loop to construct an optimal Proprotional-Integral (PI) regulator. Additionally, the differences between those two control strategies are analyzed in detail. Simulation results are demonstrated to verify that those two control strategies can be applied in three-phase shunt active power filter well and own fast response. Moreover, the results show that in suppression of low frequency harmonics, the performance of the optimal PI regulator is better than the optimal state feedback controller.