Implementation of sliding mode control for a buck converter in a photovoltaic system

This paper deals with the implementation of Sliding Mode Control (SMC) for a buck type DC-DC converter in a Photo Voltaic (PV) system. The proposed sliding mode controller is used to control the duty ratio of switching signal for the buck converter to keep constant dc output voltage irrespective variations in the PV output due to changes in operating conditions. For the feasibility study, controller design, model evaluation and analysis of converter system operation, SEVIULINK models were created for the controller. Extensive simulation studies were conducted to predict the performance of the SMC under varying operating conditions and the results are compared with that of a PI controller. A buck converter is designed and fabricated and the controller is implemented using a PIC microcontroller for a 72W PV System. The effectiveness of the sliding mode controller is established by simulation as well as practical implementation.