Discrete-Time Sliding Mode Controlled Synchronous DC-DC Buck Converter

This paper proposed a new digital sliding mode control for synchronous DC-DC buck converter. In presented control law, disturbance item is considered in the dynamic equation of the synchronous buck converter to achieve fast transient response and high robustness under load and line variations. Also, stability analysis of proposed digital sliding mode control is presented. The simulation results is obtained using the MATLAB/SIMULINK software. it shows the proposed control law exhibits significant reduction in the chattering, overshoot and undershoot of output voltage response when input voltage and load changes. The proposed method reduces the chattering to about 1.1%. Also, the overshoot and undershoot values are 1.3% and 1.8%, respectively. Also, when the line voltage is altered to 26%, there is almost no overshoot and undershoot. The selected converter in this article has 38V input voltage and 5V output voltage and 10W output power.