JEE_V9_N4_RP1 Amine Daoud Journal on Electrical Engineering 2230 – 7176 9 4 1 11 Direct-Coupled System, MPPT, DC-DC Converter, Flow Rate, Duty Cycle, Shaft Speed Recently, the importance of photovoltaic systems in the generation of electricity has attracted much attention because of their electrical energy production close to where it is required, no greenhouse gas emission, low maintenance cost, and no noise. However, the promotion of photovoltaic system has been limited by two problems, low conversion rate and maximum power point varying with atmospheric conditions (irradiance, temperature and air mass). Hence, one of the most economical ways to improve utilization efficiency of a photovoltaic system is to ensure that it is always operates at its maximum power point irrespective of the environmental conditions. Thus, it becomes necessary to use MPPT controller in order to ensure the efficient operation of the photovoltaic system. Within this overall context, the present paper focuses specifically on the development of new Maximum Power Point Tracking (MPPT) technique used in Photovoltaic (PV) water pumping systems. Furthermore, using this technique, only the input voltage of a PV array needs to be sensed in order to find and track the MPP. The system under study consists of a PV array, a DC-DC buck-boost converter, a DC motor-pump and an MPPT controller. This pumping system is fully modeled and simulated in MATLAB environment. Analytical models for determining PV array output power, motor-pump flow rate and shaft speed are detailed and explained. The simulation results demonstrate that the proposed MPPT technique can track the MPP perfectly. April - June 2016 Copyright © 2016 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=6034