Study On Intelligent Water Outlet Control Of Photovoltaic Pump Systems In Mountainous Area

There are many seasonal and engineering mountainous areas in the southwest of the country that are short of water and have insufficient electricity supply,which cannot meet the irrigation of crops.Photovoltaic pump technology has the advantages of good economy,low operation and maintenance cost and wide application range,and is an effective technical means to solve the problem of water irrigation in the arid mountainous areas of southwest China.At present,the most widely used method of water lifting in related technical fields is the"one-lifting method"or"hierarchical pumping station method",and there is a certain waste or high investment in water lifting energy.In order to solve these problems,this thesis on the basis of combining photovoltaic pump technology,sensor and detection technology and remote wireless communication technology,proposes a single-station hierarchical intelligent water lifting scheme,which intelligently controls the effluent according to the irradiance and different heights of water in mountainous areas,and controls the outlet valve of each level of reservoir through a single-chip microcomputer and a remote wireless communication module.Its main contents are as follows:（1）The performance analysis of important equipment（photovoltaic array,motor,water pump）in the photovoltaic water extraction system was carried out separately.The output characteristics of photovoltaic arrays under different irradiance and temperature conditions are studied,and on the basis of analyzing the advantages and disadvantages of centrifugal pumps,positive displacement pumps and other types of pumps,the hydraulic piston pump is determined as a water lifting device in the sample study.（2）By collecting relevant environmental data of irrigation areas（such as solar irradiation,rainfall,etc.）and analyzing the water demand of crops to be irrigated,this paper determines the optimal configuration and model selection of photovoltaic pump system,and uses Lo Ra spread spectrum wireless communication technology based on MODBUS protocol to solve the problem of remote communication and control.（3）According to the solar irradiance to achieve the intelligent control of maximizing the water output of each outlet,the work done includes hardware,software design and system debugging.Among them,the hardware design mainly completes the work of the sensor node,the gateway node and the solenoid valve node,and selects the light intensity sensor,the microcontroller,the RS485 chip and the wireless remote communication module,on this basis,the specific process of the implementation of the functions of each module is studied,and the design work of the circuit principle connection diagram and experimental debugging is carried out.The software design mainly completes the node embedded software structure and studies the embedded programming method,mainly including the main program,system initialization,interrupt programming,wired RS485 communication design and wireless communication program design based on the MOUBUS protocol.（4）In this paper to determine the water valve opening and closing control strategy,the different types of water pump,centrifugal pump and plunger pump)of photovoltaic water pumping system in sunny day,cloudy and overcast three climatic conditions,theoretical calculation and simulation experiment through the analysis found that single station classification intelligent water plan carry water effect is better than that of single station carry water,especially in cloudy conditions,the effect of water biggest increase,Compared with the single-station water lifting system,the increase percentage of photovoltaic centrifugal pump system theoretical calculation is 66.2%,and the increase percentage of simulation experiment is 62%.The increase percentage of photovoltaic piston pump system theoretical calculation is 10.2%,the increase percentage of simulation experiment is 9.8%.On this basis,the economic analysis of photovoltaic plunger pump system under single station intelligent water lifting scheme,single station intelligent water lifting scheme and multi-station intelligent water lifting scheme is also carried out.The results show that the water lifting scheme designed in this paper significantly reduces the water lifting cost,and the water lifting cost per unit volume（1m~3）is 19.9%and 14.6%lower than the multi-station graded water lifting scheme and the single station water lifting scheme,respectively,reaching the expected design goal of reducing the waste of water lifting energy and reducing the cost.