MODELING OF SYSTEMS WITH THE PHOTOVOLTAIC POWER SOURCE AND WATER PUMPS

Abstract

The article is devoted to the calculation of systems consisting of a solar photovoltaic power source and water pumps. It is noted that such systems can be used both in households or industry, and in agriculture, in particular for irrigation. Several variants of water pumps are shown. An analysis of the operational modes where the photovoltaic power source is connected to the pump has been carried out. The selection of equipment was carried out and the expediency of using a system with an electric energy booster was indicated. A booster for providing current during start-up modes can be a capacitor, a battery of capacitors or an ionistor. Emphasis is placed on the fact that for doing of such systems it is necessary to apply modeling with the use of electrical models. It is shown that for developing of electric models of solenoid-based pumps and pumps based on rotating direct current motors, it is necessary to use the methods of electromechanical analogies. Electrical models of a photovoltaic power source and, based on analogies, a solenoid-based pump and a direct current motor-based pump with permanent magnet excitation and parallel excitation were developed. When developing electrical models, controlled sources of voltage and current were used with mutual influence of the electrical and mechanical parts of the pumps. The need to use direct current motors with parallel excitation is indicated, as they are more stable to emergency modes. It is also stated that in general, the mechanical load of the rotating part of motors is non-linear and depends on the number of revolutions of the shaft. A nonlinear resistance that models a nonlinear mechanical load is shown, and it is noted that the higher-order nonlinearity is insignificant. Conclusions are drawn and further development in the direction of the use of digital technologies is outlined.