Non-singular terminal sliding-mode control of DC–DC buck converters

This paper presents a non-singular terminal sliding mode control (NTSMC) method for DC–DC buck converters. The NTSMC method eliminates the singularity problem which arises in the terminal sliding mode due to the fractional power and assures the finite time convergence of the output voltage error to the equilibrium point during the load changes. It is shown that the NTSMC method has the same finite time convergence as that of the terminal sliding mode control (TSMC) method. The influence of the fractional power on the state trajectory of the converter is investigated. It is observed that the slope of the sliding line becomes larger with decreasing value of the fractional power which leads to a faster transient response of the output voltage during the load changes. The theoretical considerations have been verified both by numerical simulations and experimental measurements from a laboratory prototype.

► A nonsingular terminal sliding mode control is presented for DC–DC buck converters. ► The method eliminates the singularity problem. ► Also, it assures finite time convergence of the system states to the origin. ► The effect of the controller parameters on the performance of the system is studied. ► Simulation and experimental results show the performance of the method.