Research on photovoltaic water pumping system based on valve opening model

Photovoltaic water pumping system (PVWPS) is an important way to use solar energy. In order to further improve the solar energy utilization rate of PVWPS, this study proposes a valve opening model, which solves the problem of more solar energy waste caused by fixed pipeline characteristics under different irradiation intensities. Firstly, the theoretical calculation formula of pipeline flow is deduced according to the balance relationship between photovoltaic energy supply and energy demand of water lifting pipeline in PVWPS, and its working principle is expounded. Finally, the function model of pipeline flow-valve opening-radiation intensity is derived from the cycle test of PVWPS, and the PVWPS with water lifting height of 10 m, 12 m and 14 m is verified by all-day test. Compared with the unregulated valve, the cumulative water extraction of the PVWPS with three water lifting heights after valve regulation is increased by 15.85 %, 18.06 % and 80.71 % respectively, indicating that the cumulative water extraction of the PVWPS can be effectively improved by adjusting the valve opening. This study provides a new idea for improving the utilization rate of solar energy in PVWPS.