Research And Design Of Magnetic Resonance Wireless Power Supply System

Electricity,as a clean energy,has a very high utilization rate in China,but at the same time it has also caused a series of new social problems such as difficulty in charging and power consumption.Wireless power transmission technology is a new application method of electric energy,which solves the hidden dangers of traditional wired power supply wire damage and short circuit.Among them,magnetic resonance wireless power supply technology has long power supply distance,high efficiency and penetration compared with other wireless power transmission schemes.It is the most research-worthy wireless power supply technology currently.This thesis provides a comprehensive introduction and detailed comparative analysis of wireless charging technology.Aiming at the current academic research on magnetic resonance wireless charging systems,the necessity of researching the system under different ambient temperatures is proposed.The specific research plan is as follows:First of all,based on the working principle of wireless power transmission technology,circuit theory is used to compare and analyze the advantages and disadvantages of S-S and SP topological structures of magnetic resonance wireless power supply system,and the S-S topological structure is selected as the system topology in this paper according to the system design goals.Select the appropriate load through formula derivation to avoid frequency splitting in the system.Based on the SS topology combined with the environmental temperature to study the characteristic factors that affect the system transmission efficiency,MATLAB and MAXWELL simulation software are used to simulate and analyze the relationship between the coil parameters,the transmission distance and the system transmission efficiency,and it is concluded that the environmental temperature can be changed by changing the load and the coil.The parameter value in turn affects the transmission efficiency of the magnetic resonance wireless power supply system,and the degree of influence increases with the increase of the transmission distance.In order to avoid the environmental temperature acting on the additional coil loss resistance at the same time to cause the system transmission efficiency loss to increase,the optimal number of turns is found through simulation analysis to make the system reach the best transmission state.Secondly,according to the block diagram of the magnetic resonance system,a magnetic resonance wireless power supply system with a resonance frequency of 185 KHz is designed,including a primary circuit,a coupling circuit,and a secondary circuit.In the design of the primary circuit,the half-bridge inverter topology is selected as the main circuit of the system inverter,and the hardware design of its drive circuit is carried out;in the design of the coupling circuit,according to the simulation analysis results of the coil parameters,combined with the optimal number of coil turns,Design the magnetic resonance wireless power supply coil,and select the NPO capacitor with good temperature characteristics as the system resonance capacitor;in the secondary circuit design,the hardware design of the bridge rectifier circuit is carried out.Finally,set up a temperature experiment device for the magnetic resonance wireless power supply system,and use a vector network analyzer to verify the correctness of the magnetic resonance wireless power supply system design.The measurement results show that the system transmission efficiency reaches the highest at the resonance frequency of 185 KHz.The experiment measures the transmission efficiency of the system when the number of coil turns is different,which verifies the simulation conclusion that the system transmission efficiency is the best when the inner diameter of the coil is equal to the outer diameter.The experiment measures the influence of the environmental temperature on the system under different transmission distances.The data shows that the transmission efficiency of the system decreases with the increase of the environmental temperature,and the degree of decrease increases with the increase of the transmission distance,verifying the correctness of the simulation conclusions.