Switching function optimization of sliding mode control to a photovoltaic pumping system

Abstract

The research deals with the performances of an asynchronous motor coupled to a pump in terms of optimal photovoltaic transfer, using the concept of variable structure systems by sliding mode. The main advantage is to implement a robust sliding mode control from a nonlinear system. The contribution of this work is modeling a new switching surface. The control law is based on adding an integral term for the considered surface in order to improve the performances of the system. Moreover, a sliding mode control technique associated with a boost converter is used to extract the Maximum Power Point Tracking (MPPT). In the first part of this chapter, a general modeling of the different elements of the photovoltaic pumping system is presented. In the second part, a methodology of synthetizing sliding mode control is developed with the choice of a novel switching function. The proposed control law acts on the duty cycle applied to a boost converter in order to transfer a maximum power delivered by the photovoltaic generator to the induction motor. Finally, the validation of the results is carried out with a comparative study to show the efficiency of the proposed control.