Design and test of driving power and photovoltaic power matching for solar-driven sprinkler irrigation unit

Abstract: The development of effective irrigation machine is one of the factors which can promote the development of agriculture and increasing crop yield. Facing the shortage of energy and limitation of water resources, the development of agricultural irrigation has been constrained. Removable sprinkler irrigation has been widely used due to its high automation, labor saving, and many other advantages. However, a stable power supply is needed, especially in some remote areas where the maximum electricity cannot be fully guaranteed. This may lead to water shortage for crops, and such areas usually cannot be timely irrigated. The solar-driven sprinkler unit can save energy and water. It is of great significance to improve the efficiency of farmland irrigation, reduce labor costs, and solve the problem of irrigation power in the areas where energy is in shortage. In order to improve irrigation efficiency, reduce labor cost, and solve the problem of irrigation power in those areas, the present research was carried out on the driving force demand and the photovoltaic power matching of the unit through the solar energy to drive sprinkler irrigation, which was developed by our research group. According to the characteristics of the unit structure and the driving power, a dynamic design and matching design method of the solar energy drive sprinkler unit were constructed by theoretical calculation of the power supply and demand of the unit. The calculated power of the driving demand was verified through experiments. The typical working hours and designed daily standard working hours of the typical sunny summer units were evaluated for the working capacity of the unit and the power supply capacity of the PV system. The results showed that the measured value of travel drive power was basically consistent with the theoretical calculated value, and the maximum relative error was 7.3%, indicating the reliability of the calculation of travel drive power. At the typical summer sunny day, the maximum cumulative working time of the unit increased with the decreases in irrigation power and running speed of the unit. Taking the tested day as an example, when the unit reached the maximum designed flow, the maximum operating speed was then in the maximum load condition and the maximum working time was about 20 hours, showing a stronger ability of the unit. A one-month PV power supply monitoring was conducted in Jul, 2016 on the basis of daily designed duration of 8 hours. And this made a study on power supply capacity through the horizontal of the system. The results showed that during the one-month detection process, the total systematic power shortage duration was about 8.75 hours, accounting for about 3.5% of the total power supply duration. This indicated that the photovoltaic power supply system had a high reliability. This study can provide references for realizing the combination of solar energy and agricultural machinery, designing and optimizing drive system of the solar-driven sprinkler unit, promoting the popularization and application of solar powered irrigation unit in engineering, and solving the problem of irrigation power shortage in the regions with less energy.