| As a large agricultural country,China’s solar greenhouse is the main part of facility agriculture,and it is very popular in the northern region.The environment of the solar greenhouse greatly affects the healthy growth of fruits and vegetables and other economic crops.As an important part of the environmental monitoring system,sensors can provide data support for the automation and intelligence of greenhouses.Currently,most sensor monitoring systems are powered by batteries.Due to the limited battery life,this will affect the continuous operation of the sensors.If long-distance wiring is used for power supply,the wiring is more complicated.Solar energy can also be used to power the sensor,but this method is extremely susceptible to environmental influences,and the sensor cannot be normally powered under cloudy conditions.Therefore,the article proposes a wireless power supply method for the power supply of greenhouse sensors and optimizes itBased on theoretical research,the article first selected a magnetically coupled wireless charging method,designed a wireless charging circuit,completed the circuit PCB drawing and coil winding,and established a wireless charging device model;the experiment found that the transmission distance of small bulbs is ≤20cm It can be lighted at intervals,and placing an obstacle between the transceiver coil will not affect the power transmission.Within a certain deflection angle,the light bulb will still light.Secondly,considering the particularity of the greenhouse environment,a rail-type mobile trolley was designed to place the wireless charging device;the selection of each device and the design of some programs were completed.Afterwards,the transmission characteristics of the magnetically coupled wireless charging system were analyzed by ComsolMultiphsics5.4 multiphysics simulation software,and the following conclusions were obtained.The efficiency of wireless energy transmission increases with the increase of the coil wire diameter and radius;Increase,showing the trend of first rising and then decreasing,the number of turns is about 12 turns,the transmission-efficiency of the system reaches the maximum;as the distance between the two coils increases,the transmission efficiency of the magnetically coupled wireless charging system decreases significantly;the transmission efficiency As the system frequency increases,it increases.When the frequency is greater than 275,the transmission efficiency tends to be stable;the system transmission efficiency decreases linearly with the increase of the load resistance.Finally,the interference between adjacent wireless power supply systems is studied.The equivalent circuit model of the dual-group wireless energy transmission system is established,and the three situations when the two systems are coaxially distributed are analyzed.When the transmitting coils of the two systems are on the same side,the magnetic field distribution is asymmetric,and the receiving coil located between the two transmitting coils has a higher transmission efficiency;when the transmitting coils of the two systems are located on the opposite side or the different side,the magnetic field distribution is symmetric Distribution,the transmission efficiency can be improved between the systems;when the distance between the systems is greater than 1.2m,the transmission efficiency of systems 1 and 2 tends to be consistent,and the mutual influence gradually disappears. |
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