Sliding mode control for a grid connected PV-system using interpolation polynomial MPPT approach

Abstract

In this paper, two controllers are proposed to optimize the photovoltaic (PV) energy injected into three phase grid. The first controller is used to predict the DC voltage that allows the three-phase inverter to track the maximum power point of photovoltaic generator under unbalanced climatic conditions and variable load. This new controller uses a multivariate polynomial interpolation based on the Lagrange’s theory. The second controller is based on the robust Sliding Mode Control (SMC). It is used to control the active and reactive powers injected into the network in order to achieve the maximum active power into grid with high efficiency and minimum total harmonic distortion using the same three-phase inverter. The control strategies efficiency is confirmed by simulations and experimental results. In addition, in order to validate the choice of control strategies, a comparative study was carried out.