Étude d’un système de conversion de l’énergie photovoltaïque à base d’un émulateur photovoltaïque.

Abstract

The work of this thesis focused on the practical realization of a photovoltaic emulator based on a Buck type dc-dc converter driven by a dSPACE 1104 card. The control is implemented through two closed-loop control systems, a voltage closed-loop control and a current closed-loop control (hybrid control), each loop is used to control the power stage in a specific region depending on the operating point. However, the reference signals of each loop are generated from the mathematical equation of a PV cell, whereas errors signals are composed by a PI controller. These techniques allow us to increase the stability of the system by reducing the variation of the reference signal. In addition, the proposed control strategy is adapted to include partial shading effects of two panels connected in series. Then we tested the stability of our emulator proposed by an adaptation stage controlled by an MPPT algorithm type P&O. The simulation of the proposed system is carried out under MATLAB-Simulink and the results obtained are compared with the experimental results. The results obtained show that our emulator is able to generate the different characteristics (I-V) and (P-V) in the different weather conditions, including the partial shading conditions ,on the other hand it is able to evaluate any MPPT algorithms.