Design and realization of a descretized PV system with an improved MPPT control for a better exploitation of the PV energy

In this paper, we present results concerning the design, the realization and the characterization of a photovoltaic system (PV), equipped with a digital controls: Power Point Tracking (MPPT), charge/discharge lead acid batteries, sun tracker and supervision. These different functions are performed with a microcontroller that has capabilities and functions to the reliability of PV systems (signal generation Pulses Width Modulation (PWM), speed etc.). Concerning the MPPT control operation, we improved the accuracy and reliability of research by improving the search algorithm “Hill Climbing” taking into account the optimal operation of PV panels depending on weather conditions (temperature and light).The experiment of each block shows that the MPPT control converges instantly the operating point of the PV panels around the maximum power point, independently of sudden changes of the illumination or the load. The control blocks charge/discharge battery and sun tracking show good control of charge/discharge lead acid batteries and the need of sun tracker to increase the power supplied by the PV panel. By using the improved MPPT control, loss of power supplied by the PV panels are very low (below 5%).

Dans cet article, nous analysons la conception et la simulation du fonctionnement électrique d’un système photovoltaïque (PV) adapté par une commande analogique (commande MPPT) assurant la poursuite de la puissance maximale fournie par le générateur PV. Les résultats obtenus montrent que le système PV ainsi conçu converge au bout d’un temps de l’ordre de 50 ms vers les conditions optimales indépendamment des conditions météorologiques et de la variation de la charge. Dans notre analyse, nous avons conçu un système PV où le générateur PV est le module SP75 produisant, dans les conditions standard de test (CST), une puissance crête de 75 W, un courant optimal de 4.41 A et une tension optimale de 17 V.