Sensorless Robust Controller for Buck Converter using Modified Fast Terminal Sliding Surface

This proposes a higher order Sliding mode control strategy to regulate output voltage of dc-dc buck converter affected by line and load uncertainties. The control objective is to regulate the output voltage in presence of change in input voltage and load value is met by designing an observer based super twisting algorithm (STA) for modified fast terminal sliding surface (FTSM). The ability of Luenberger observer and controller in regulating output voltage and tracking reference voltage analyzed. The controller and observer performance is simulated in Matlab and compared with different sliding surface.The simulation results of modified FTSM are superior than conventional Linear sliding surface (CLSS).