Performance of the adaptive sliding mode control scheme for output voltage control of the DC/DC buck converter system

Abstract

In this work, the DC output voltage of a step-down DC/DC buck converter system has been controlled using different schemes of sliding mode controllers (SMCs) such as classical sliding mode controller (CSMC), modified sliding mode controller (MSMC) and the adaptive sliding mode controller (ASMC). As the DC/DC buck converter is a nonlinear and time-variant system, the application of linear control techniques for controlling this type of converters is not always suitable. Therefore, the SMCs are used here due to their characteristic features of maintaining the overall system stability with acceptable performance in the absence or presence of the parameters uncertainty and external disturbance. The simulation results obtained using MATLAB/Simulink software show the advantages of using ASMC in terms of reducing the settling time, the chattering value in the control action and the steady state error but the hitting time is increased when compared with the CSMC. Besides, the simulation results show the advantages of using ASMC in terms of reducing the settling time and the chattering value, but the steady state error and the hitting time are increased when compared with the MSMC. Since the buck converter is a fast response system, the performance of the ASMC is better than that of the CSMC and MSMC in terms of reducing the settling time and the chattering value in the control action.