Adaptive Continuous Sliding Mode Control of Buck Converters with Multidisturbances Based on Zero-Crossing Detection

In this paper, a novel adaptive continuous sliding mode (SM) control approach is proposed based on the robust stability analysis of buck converters with multi-disturbances. Instead of the traditional first-order SM methods, the twisting algorithm is adopted to realize the control continuity and further weaken their inherent chattering problem. By introducing the zero-crossing detection innovatively, the influence of the traditional twisting algorithm with fixed control gain led to the low precision is effectively eliminated, and the small region can be controlled due to the implementation of the adaptive time-varying control gain. In addition, the magnitude of the controller can be reduced to a minimal admissible level determined by the system stable conditions and the selection of optimization parameters. Furthermore, multiple model uncertainties and external disturbances are considered into the modeling of the buck converters and the proposed adaptive SM controllers to ensure the strong robustness of the whole system while suffering possible disturbances. Finally, comparative simulations and experiments are given to validate the effectiveness of the proposed adaptive control strategy.