Implementing sliding mode control for buck converter

The theory of sliding mode control (SMC) to switch mode power supplies have been widely investigated in literature, but most of the papers have focused on the theoretical aspects of this control without any practical implementations. This paper links the theory to practical power supply design. Analysis and experimental study of buck converter is presented, and nonlinear state feedback control is derived to achieve desired output voltage. The paper focuses on modelling a control circuit in Matlab/Simulink™ and implementing it to the buck converter. Next, a prototype with SMC is build up. The output voltage and inductor current of the both models are compared in steady state mode and under line and load variations. The efficiency is also calculated from the measurements made with the prototype. All these measurements showed advantageous results.