A Second-Order Sliding Mode Control Scheme With Fuzzy Logic-Based Online Sliding Surface Adjustment for Buck Converters

This paper proposes, a second-order sliding mode control-based scheme for the closed-loop control of DC-DC buck converters. The proposed control technique adjusts online the sliding surface of the second-order sliding mode controller to enhance the dynamic performance of the closed-loop system. The sliding surface adjustment is achieved by a single-input, single-output fuzzy logic inference system based on sliding variables. While maintaining its simplicity concerning design and implementation, the controller makes sure the system achieves the design requirements in terms of improved dynamic performance, stability, and robustness. Theoretical analysis confirms the global finite-time error convergence of the buck converter system. The performance of this novel control approach is compared with that of the conventional second-order sliding mode controller with a pre-defined sliding surface using SIMULINK-based simulations for a buck converter model. From the analysis of the simulation results, it is concluded that the proposed controller provides a remarkable improvement in the dynamic performance of the buck converter control system compared with the conventional second-order sliding mode controller with a pre-defined sliding surface.

Keywords: Buck converter, second-order sliding mode control, sliding surface adjustment, Mamdani type fuzzy inference, chattering attenuation.