1 Fuzzy logic control of Maximum Power Point Tracking for Photovoltaic system Youcef Soufi #1 , Mohcene Bechaouet #1 , Aziz Boukadoum #1 , Tahar Bahi *2 #1 Labget Laboratory, Department of Electrical Engineering, University of Tébessa, Algeria *2 Department of Electrotechnic, University of Annaba, Algeria 1 y_soufi@yahoo.fr, mohcene.oui@gmail.com, azizboukadoum@yahoo.fr 2 tbahi@yahoo.fr Abstract— In this paper, a fuzzy logic control (FLC) based “Mamdani” is proposed to control the maximum power point tracking (MPPT) for a photovoltaic (PV) system. The proposed technique uses the fuzzy logic control to specify the size of incremental current in the current command of MPPT. As results indicated, the convergence time of maximum power point (MPP) of the proposed algorithm is better than that of the conventional Perturb and Observation (P&O) technique. Keywords— Photovoltaic system, MPPT, FLC, P&O I. INTRODUCTION Fuzzy logic has been considered as an efficient and effective tool in managing uncertainties and nonlinearities of systems since Zadeh’s seminal paper [1] was published. A Fuzzy Controller is generally designed in the light of experience and expert knowledge [2]. The knowledge base of a Fuzzy Logic Controller (FLC) contains two components, namely, a fuzzy rule base and a data base [3], both being closely related to the concept of a linguistic variable [4]. A rule-base, i.e., a collection of fuzzy IF–THEN rules, is used to describe a particular control strategy. One of the most simple and popular techniques of MPPT is the Perturb & Observation P&O technique. The main concept of this method is to push the system to operate at the direction which the output power obtained from the PV system increases. PV system cannot be modeled as a constant DC current source because its output power is varied depending on the load current, temperature and irradiation. Generally, MPPT is adopted to track the maximum power point in the PV system. The efficiency of MPPT depends on both the MPPT control algorithm and the MPPT circuit. The MPPT control algorithm is usually applied in the DC-DC converter, which is normally used as the MPPT circuit. Typical diagram of the connection of MPPT in a PV system is shown in Fig. 1. In this paper, we propose a comparison between P&O and a fuzzy controller for Mamdani zero-order. II. PHOTOVOLTAIC EQUIVALENT CIRCUIT The model of solar cell can be categorized as p-n semiconductor junction; when exposed to light, the DC current is generated. As known by many researchers, the generated current depends on solar irradiance, temperature, and load current. The typical equivalent circuit of PV cell is shown in Fig. 2 [5]. Fig. 1 Typical diagram of MPPT in a PV System Fig. 2 Typical circuit of PV solar cell