Study On Photovoltaic Pumping Irrigation In Large-scale Rice Planting Area In Jiansanjiang Of Heilongjiang Province

With the exhaust of traditional energy and need to achieve sustainable development,the existing global energy supply structure imposes many challenges to global economy development.To cope with these challenges the governments of many nations have made decisions to develop and utilize renewable energy.Among the sources of renewable energy solar energy is highlighted due to its large distribution,clear and sustainable.The application of using photovoltaic pumping irrigation is one of promising areas of solar energy application.Based on the unstable variation of solar radiation during daytime,the research developed two photovoltaic pumping irrigation models for the large-scale paddy rice cultivation area in Jiansanjiang in Helongjiang Province of Northeast China.Based on the research the concepts of control area,spillover area of photovoltaic pumping irrigation,and maximum control area of photovoltaic pumping irrigation by combing with electricity power supply grid.The two models are optimized and sensitivity analysis is conducted based on the operation modes and conditions.The main results and conclusions of the paper are as followings:1.The assessment of solar energy in Jiansanjiang area is conducted.Based on the analysis of the assessment it is concluded that photovoltaic pumping irrigation could be applied.The solar energy distribution function model in the research area is formulated based on the solar radiation materials in the area.2.Developed the photovoltaic water pump efficiency model.Combined with photovoltaic performance model,the paper analyzes the path of solar power to pump water efficiency conversion and the correlation between the output power of photovoltaic power generation system and the output power of the pump,put forward the photovoltaic water pump efficiency model.3.The control-area model of photovoltaic pumping irrigation is developed and the sensitivity analyses of related parameters are conducted.The optimal control-area model is formulated based on photovoltaic characteristics convertor efficiency and pump characteristics and paddy rice irrigation schedule.With the model the optimal photovoltaic system power is calculated.The solar radiation sensitivity analysis result shows that due to the limitation of the rated power and rated speed of the pump system,the system efficiency is not higher with the lager of solar radiation intensity,PV conversion efficiency and PV system peak power.4.Developed three concepts of control area,spillover area of photovoltaic pumping irrigation,and maximum control area of photovoltaic pumping irrigation.Based on the theoretical analysis framework of "one factor + two operation modes +three conditions",this study developed three concepts of control area,spillover area of photovoltaic pumping irrigation,and maximum control area of photovoltaic pumping irrigation by combing with electricity power supply grid about PV pumping system based on the public network coverage area.The study lays a theoretical foundation for model optimization under various modes.5.According to the each component characteristics of the photovoltaic water pumping irrigation system,the study builds the photovoltaic water pumping irrigation system efficiency analysis model.Based on "one factor + two operation modes + three conditions"analysis theory,puts the coupling mode as the research core,the study analyzes the sensitivity of the optimal parameters and explores the double control method for photovoltaic water pumping irrigation system.The economic evaluation on project status result shows that the grid-connected benefits of photovoltaic system have great influence on system evaluation.In the process of promotion of PV system,It is necessary to consider the grid-connected benefit.Each combination model was optimized in the 75%irrigation guarantee rate with different optimization objectives based on the PSO algorithm.The maximal economic benefits are from the first and second sciences with obviously irrigation benefits,the maximum values of each parameter,and the largest economic benefit.The optimal parameters are the ratio of the benefit-cost ratio is 1 under the third science.The study analyzes the sensitivity of the optimal parameters of the coupling mode based on the economic benefit models.As the price of pv panel decreases,its marginal benefit increases gradually.With the increasing of the electricity price of grid-connected,the ratio of benefit cost increases linearly.The electricity price parameters of the public grid are more sensitive in pure PV operation mode.The outcomes of the research could provide technical support for the application of photovoltaic pumping irrigation in the area.