Nonlinear control of active power filter based on LQR control

Abstract

In order to improve the ability of real-time tracking and compensating harmonic of three-phase active power filter (APF), a nonlinear sliding mode control strategy of APF is proposed based on the state feedback linearization theory. In order to improve the dynamic performance and tracking ability of APF system, the affine nonlinear model of APF system is established, and the nonlinear control strategy of current inner loop is designed. The control parameters are adjusted by LQR method. In order to adjust and stabilize the DC voltage of the system, the slip mode control (SMC) is used to design the voltage outer loop. The simulation and experimental platform are built. The experimental results show that the method has good dynamic response, steady-state characteristics and robustness.