Abstract:Aiming at the matched and mismatched disturbances in Buck converters, a method based on generalized proportional integral observers (GPIO) and variable rate reaching law control method is proposed. First, Design a generalized proportional integral observer to estimate matched and mismatched disturbances, and the estimated value is introduced into the controller for feedforward compensation. Then, a variable speed reaching law based on the hyperbolic tangent function is constructed, which can shorten the arrival time of the system and reduce the chattering phenomenon in the sliding phase. Combined with Generalized Proportional Integral Observer, it has good anti-interference performance and tracking performance. Finally, it proves the convergence of the observer and the stability of the closed-loop control system. It is verified by simulation that this method can effectively suppress the influence of disturbance, and improve the anti-interference performance of the entire system.