In the field of electric power manufacturing, thermal power and hydropower, the two major power sources, have been the most dependent energy of human society, from the large-scale mining of electricity, water and fire almost accounted for the power field. Photovoltaic power generation started late, the initial application is only limited to the power generation industry, and then solar energy in the field of street lights out of the cocoon, the use of solar panels stored electricity for street power, than solar energy is more widely used in daily life, such as household solar appliances, solar environmental protection green cars, etc., in the space field has a seat. In fact, regarding the application of solar energy, many experts and scholars have also proposed that it can be extended to agriculture. It is a good research direction to use solar energy to support agricultural production and realize the double innovation of the solar energy industry and agricultural planting industry. Photovoltaic ecological agriculture can not only save a lot of land resources but also maximize the use of solar thermal resources to warm the greenhouse, so as to normal production of crops . Through the support of solar energy, greatly save the face value of the required land, the use of photovoltaic power generation intelligent tracking system, to achieve the maximum value of solar power generation, according to this development of a set of solar agricultural intelligent control system, to achieve agricultural intelligence, improve crop production and quality.
1 Photovoltaic intelligent tracking concept
Photovoltaic power generation can effectively solve the problem of power supply in areas without electricity, and is applied in water intake irrigation, oxygen supply of fish ponds, desert management, grassland animal husbandry and other fields . And how to greatly improve the efficiency of photovoltaic power generation in limited areas, materials, and equipment factors. Can design a set of solar intelligent tracking device, the principle is that according to the application of photoelectric sensor, develop a tracking module for weak light, such as photoresistor can be used as a light signal capture element, the photoelectric characteristics of photoresistor, the perception of light, the development of a signal acquisition module based on photovoltaic tracking system. For the working theory of photoresistor, the phenomenon of intrinsic absorption or impurity absorption after some substances absorb the energy of photons, which changes the conductivity of substances is called the photoconductivity effect of substances . The photoresistor has a unique perception of the intensity of light, and its photoelectric characteristic is that its resistance is inversely proportional to the external light. The stronger the light intensity, the smaller the resistance, so that the corresponding signal can be generated to complete the pursuit of light. The photoresistor circuit diagram is shown in Figure 1. The photoresistor is added in the solar power generation system, and the stepper motor is used as the output executive device to drive the solar panel to chase the sun light. On how to build an intelligent tracking system for solar photovoltaic power generation, its idea is shown in Figure 2. On the tracking solar panel, a solar signal acquisition device is added. The whole system includes: Central processing system (here can be used small size, processing information speed, high accuracy, long life and other advantages of single-chip processing), stepper motor, solar panels, composed of a unified photovoltaic tracking system. In the field of intelligent tracking of solar photovoltaic power generation, the most important thing is to ensure that solar panels do real-time apparent motion under the light of the sun (similar to the sunflower chasing the sun effect), in order to ensure that the solar power generation reaches the maximum, so as to ensure sufficient agricultural electricity. In the output of the solar electromagnetic panel, solar power generation belongs to direct current, so for some direct current electrical appliances, can be directly used, so in the agricultural electricity for alternating current, but also need to do further processing of solar direct current, according to this, you can in the farm free places, a large number of construction of the power generation system, the generated electricity through rectification, Inverse processing, applied to agricultural development. In the growth process of crops, proper light and soil moisture are indispensable. Light and moisture are very important factors for plant growth, which are not conducive to large-scale scientific planting of agricultural products based on the experience of workers. Therefore, the design of intelligent agricultural greenhouses plays a key role in crop growth and saving manpower and material resources . In this way, agriculture can improve the energy required by electricity through the construction of greenhouses, and the computer control system (can be used as an integrated circuit single-chip microcomputer) to regulate the light intensity; Adjust the humidity of crop growing environment; Carbon dioxide concentration in agricultural greenhouses; Promote photosynthesis of crops to achieve the purpose of increasing crop production in a limited regional environment. In terms of irrigation, solar photovoltaic water lifting system should be built . In the treatment of pest control, the frequency of light that is not suitable for pests can be emitted through different lamps to inhibit pests, of course, this is done under the premise of not harming the plant. Take it one step further. Solar photovoltaic power generation tracking intelligent system is as the basis of intelligent agriculture, according to solar power generation as an important energy source for the development of the entire agriculture, to achieve artificial regulation of agricultural production, to break the original agriculture by climate, regional restrictions, fully realize agricultural intelligence.
2. Solar photovoltaic agriculture program research
In order to make the combination of photovoltaic power generation and agricultural production of light compensation photovoltaic agriculture has the highest economic benefits and maximum application value, this paper describes an application of solar photovoltaic agriculture scheme. In order to maximize the efficiency of light utilization, three-dimensional planting + greenhouse planting mode is adopted in agricultural production. The three-dimensional planting model can produce more crops in a limited land area. For artificial blue and purple light sources and red light sources, they are point light sources, point light sources are divergent, three-dimensional planting can better absorb the light. Greenhouse planting mode can effectively control the temperature and humidity of the crop growing environment, and also effectively reduce the evaporation of water. In the solar equipment of photovoltaic power generation, the installation of power generation equipment is not suitable for large-scale construction, so that crops can absorb enough light for photosynthesis. An efficient solar tracking system is critical. The purpose of using solar power generation is to store solar energy in the form of electrical energy first, and when the light reaction stage of photosynthesis lacks light energy, the electric energy stored in the battery will be converted into blue violet light and red light for plant photosynthesis to provide light energy. In order to provide enough power to support the duration of optical compensation, the capacity of the energy storage device (capacitor) should also be large enough. As shown in Figure 3, the structure diagram of intelligent agriculture integrated with photovoltaic power generation is conceived in the figure. In the greenhouse, lay a variety of sensors, used to detect the parameters of the greenhouse, through the data transmission to the computer control system, so as to achieve the greenhouse inside the CO2 concentration, temperature, light intensity, soil moisture and other comprehensive intelligent control, in order to achieve the production effect of intelligent agriculture. According to the ladder structure of 3 and 4 in Figure 3, spatial three-dimensional agriculture can be developed to maximize the use of land. At the same time, soilless cultivation of crops can be developed on this basis. By mixing the nutrients needed for crop growth in irrigation water, the PID control method of computer intelligent system can be used to regulate the flow of water. In this way, the water in the root of the crop is replaced repeatedly in a timely manner, so as to ensure that the water in contact with the root of the crop will not be too much waste, which will lead to the phenomenon of root necrosis and ensure the healthy growth of the crop. In general, through human subjective, crops growing under natural conditions, through the establishment of greenhouses, the external growth environment of crops to make regular regulation, and the external environment in line with the growth environment of crops, and all these will be deployed through the computer control system, through intelligent adjustment, can provide the most suitable growth environment for the growth of crops. In this basically, reduce the input of labor costs, because the light energy required for plant growth, the electric energy required for control system, the energy of greenhouse operation are from photovoltaic solar energy, in theory, the energy of photovoltaic solar greenhouse can be self-sufficient, greatly saving agricultural production costs.
3 Application of photovoltaic power generation in agriculture
The use of solar power generation to achieve agricultural field irrigation system, solar temperature detection in greenhouse planting, intelligent control of photovoltaic greenhouse planting, solar insect killing lamp (solar insect control) and so on. Insect-inducing lamp uses the reaction behavior generated by insects to attract the corresponding wavelength of light waves to the high-voltage power grid. The high-voltage power grid is around the insect-inducing lamp. When the flying insects are lured by the light, they will fly towards the lamp tube and first encounter the high-voltage power grid before getting close to the lamp tube. Complete the killing of flying insects . In order to complete the insecticidal operation, reduce the use of pesticides, open up green agriculture. Figure 4 shows the schematic diagram of agricultural intelligent regulation system based on solar energy, in which the energy required comes from solar panels, according to the intelligent tracking system of photovoltaic power generation, to achieve the maximum limit of solar power generation, and the generated electricity is directly applied to the agricultural intelligent regulation system of solar energy and agricultural product processing. The surplus electricity can be stored by batteries, connected to the grid, or according to local conditions, the construction of small pumped storage power stations (which can be used as reservoirs in agricultural irrigation systems) to store electricity. Among them, the computer intelligent adjustment system takes the agricultural greenhouse as the control object, takes the corresponding amount of temperature, brightness, air water content and so on in the agricultural greenhouse as the adjustment parameters of the adjustment system, and can be adjusted by the proportional integral differential regulator (PID) of the intelligent control system, so that various parameters in the agricultural greenhouse are the most suitable environmental factors for crop production. Of course, each crop is different, and its production environment also has a different growth environment. In the process of system design, a new type of solar power glass film greenhouse is selected. This new greenhouse replaces the original plastic film with photovoltaic glass film, and changes the south wall of the greenhouse into a solar panel, making full use of the achievements of the photovoltaic industry, organically combining the photovoltaic industry with agriculture, and improving the environmental protection and resource utilization compared with the traditional plastic film greenhouse . Therefore, in the design of an agricultural greenhouse, when the crops are sown, the required parameters should be set when the computer is adjusted. Or choose different crops with the same growing environment for mixing, which greatly improves the space utilization of agricultural greenhouses and increases crop yields.
Food and crops as the basis of human survival, since ancient times there has been a saying that the people depend on food. The importance of crops is self-evident. And for the start of 2020, natural disasters are frequent. The world food problem caused by the locust plague is very serious. From the perspective of intelligent photovoltaic agriculture, this paper develops a photovoltaic + agriculture model with light compensation to achieve intelligent agricultural photovoltaic power generation tracking system, which facilitates crop growth and increases crop yield, and can alleviate the problem of food shortage to a certain extent. This model expands the application of photovoltaic in agriculture, promotes the development of the photovoltaic industry to a certain extent, and also provides a solution for the high yield of agriculture.