Pompage d'Eau par Energie Photovoltaïque Expérimentation et Simulation

Abstract

This research evaluated the experimental study carried out to investigate the performance of a simple, directly coupled dc photovoltaic (PV) powered water pumping system. The system comprises of a 1.5 kWp PV array, D.C. motor and a centrifugal pump. The centrifugal pump is from local market and designed for fixed voltage. The D.C. motor is of permanent magnet brushed type used for educational purposes. As part of this research a working directly coupled PV water pumping system is produced. The experiment was conducted under a variable dc power source with the aim of calculating different motor parameters and all measuring equipment calibration. The system was tested and monitored for its performance outdoor for short periods under different climatic conditions and varying solar irradiance and ambient temperature with two static head configurations. A second objective was to model one by one all components of the PV water pumping system to describe its performance. The calculated flow rate, head generated by the pump and the efficiency of the system as function of solar irradiance and time were compared with field-measured data. The performance of the system is assessed using field data recorded at USTO. The centrifugal pump operation is analyzed by the torque equation and its variations as a function of the rotational speed and flow rate. The pump had to be dismantled for its impeller parameters and dimensions. The recorded hourly solar irradiance at UST Oran site are arranged into four clusters representing four types of sky conditions for every month of the year. An unsupervised neural network clustering method is used (Self Organizing Map). No attempt is made to estimate the solar irradiance since the issue was previously treated by the author (in previous research work), but also because professional ii softwares are fairly available via World Wide Web (SoDa). Although the motor–pump efficiency did not exceed 30%, which is typical for directlycoupled photovoltaic pumping systems, such a system is clearly suitable for low head irrigation in the remote areas, not connected to the national grid and where access to water comes as first priority issue than access to technology. The system operates without battery and complex electronic control, therefore not only the initial cost is low but also maintenance, repairing and replacement cost can be saved. The study showed that directly coupled system attains steady state soon after any abrupt change. The increasing need for water pumping, especially for irrigation and domestic use in arid and remote areas (Sahara, steppes), together with the rising fuel costs, encouraged the development of photovoltaic water pumps.