Minimum motor losses point tracking for a stand-alone photovoltaic pumping system

Solar photovoltaic energy has been, for many years now, a promising alternative in the diversification of global energetic sources. Although photovoltaic energy has many advantages, it has not yet become commercially popular, because it is still an expensive alternative. In fact, studies have already shown that the investment in such systems are paid back, but it is still hard to find people willing to wait five or six years to have their money back. The aim of this work is to reduce the payback time of photovoltaic stand-alone pumping systems, optimizing not only the efficiency of the photovoltaic conversion, using a maximum power point tracking algorithm, but also minimizing the losses in the induction motor. Based on the design procedures described in this paper, a prototype has been developed and experimental results with the optimizing strategy are shown.