In this paper, a robust sliding mode controller for the control of dc-dc buck converter is designed and analyzed. Dynamic equations describing the buck converter are derived and sliding mode controller is designed. A two-loop control is employed for a buck converter. The robustness of the sliding mode controlled buck converter system is tested for step load changes and input voltage variations. The theoretical predictions are validated by means of simulations. Matlab/Simulink is used for the simulations. The simulation results are presented. The buck converter is tested with operating point changes and parameter uncertainties. Fast dynamic response of the output voltage and robustness to load and input voltage variations are obtained.
P. Mattavelli, L. Rosetto and G. Spiazzi, “Small-Signal Analysis of Dc-Dc Converters with Sliding Mode Control,” IEEE Transactions on Power Electronics, Vol. 12, No. 1, 1997, pp. 96-102. doi:10.1109/63.554174
J. H. Su, J. J. Chen and D. S. Wu, “Learning Feedback Controller Design of Switching Converters via Matlab/ Simulink,” IEEE Transactions on Education, Vol. 45, 2002, pp. 307-315. doi:10.1109/TE.2002.803403