Enhanced Robust Control of the DC-DC Converters Based on Reduced-Order GPI Observer

To improve the dynamic performance and anti-interference ability of the PWM-based DC-DC buck converter, an improved active disturbance rejection control (ADRC) is developed in this paper. First, the dynamic model of the converter is deployed and all the system uncertainties are treated as the total disturbance in the input channel. Different from the conventional ADRCs using an extended state observer (ESO), a reduced-order generalized proportional integral observer (RGPIO) is designed to estimate the total disturbance, which has higher estimation accuracy and faster dynamics response. Then a linear feedback control law is designed to compensate for the disturbance and regulate the output voltage, and the stability of the closed-loop system is proved through the Routh-Hurwitz criteria. Finally, the effectiveness of the proposed method is verified by simulation results.