A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1981

A theoretical study, on photovoltaic pumping is undertaken to establish the most efficient direct- coupled system and to evaluate the relative merits of a system with a maximum power point tracker (MPPT) as an interfacing device, over the direct-coupled system. An experimental study on the performance of a direct-coupled system is carried out by setting up an installation of solar panels, direct-current permanent magnet motor and centrifugal pump. Using mathematical models of the system components, it is shown that the direct- current permanent magnet motor with centrifugal pump provides the best adaptation to the direct-coupled system. Further, a comparative simulated performance study shows that the system with MPPT starts pumping earlier than the direct- coup.1ed system and that it could pump even during cloudy atmospheres. Moreover, the simulation of daily flow, throughout a year, indicates that with MPPT, t he yearly flow increases by around 25% . The effect of an eventual sun tracking system is also considered in the theoretical studies. The experimental study carried out on t h e direct-coupled sys tern concludes that the system efficiency is between 3.2 and 4.1% for heads between 4.5 and 5.5 m, with the illumination levels above 600 W/m2 . The parameters of the regression models are obtained for the working curve of the system and for the characteristics of the pump, The performance curves are also given.