Research on underactuated characteristics and nonlinear control of the active power filter

Abstract The active power filter (APF) is taken as the control object in this paper and the underactuated characteristics of the APF are analysed based on the underactuated theory. Based on theoretical analysis, appropriate state variables were selected as the driving variables and underactuated variables, and a partial feedback linearization method based on underactuated theory was used to design the current inner-loop controller. The active disturbance rejection control (ADRC) was used for the voltage outer-loop design to improve the ability of the DC voltage and resist disturbances from the power grid and load. The simulation and experimental results show the correctness and effectiveness of the control strategy, and the APF control system has excellent dynamic performance and steady-state accuracy.