A sliding mode active disturbance rejection control of DC active power filter for enhancing DC microgrid voltage robustness

• Second harmonic suppression. • Improve the anti-interference capability of DC APF . • Enhance DC microgrid voltage stability. • Simple controller implementation. Under nonlinear loads, the voltage quality of DC microgrids will decrease. Generally, adding DC active power filter (APF) is an effective method to suppress the voltage harmonics of DC microgrids. To improve the anti-interference ability of DC APF, a sliding mode active disturbance rejection control (SM-ADRC) is proposed in this paper. Firstly, based on the dynamic model of the DC APF, an SM-ADRC control is designed to stabilize the capacitor voltage of the voltage outer loop. Secondly, a Deadbeat control is applied to accurately track the harmonic currents of the current inner loop. Due to the sliding mode control (SMC) and the active disturbance rejection control (ADRC), the anti-disturbance performance of DC APF under system parameter disturbance is improved, which can accurately and effectively compensate the voltage harmonics in DC microgrid. Finally, the effectiveness of the proposed control strategy is verified by simulation and experiment.