Thermal Characteristics Analysis And Optimization Of Magnetic Coupling Mechanism Of Wireless Charging System

Compared with traditional contact-type wired charging,wireless charging technology has the advantages of flexibility,convenience,safety and reliability,and strong environmental adaptability.It is widely used in household appliances,transportation,biomedical and other fields.In the wireless charging system,the magnetic coupling mechanism is the core component to realize the electric energy transmission,and it will produce a certain amount of heat due to the electric energy loss when it works.This heat is not conducive to the dissipation of magnetic coupling mechanisms that are often installed in cramped spaces,and can easily cause the temperature of the magnetic coupling mechanism to rise,thereby reducing the safety and reliability of the system.This dissertation first compares several typical wireless power transmission methods,takes magnetic coupling resonant wireless charging as the research object,expounds its working principle and four types of basic compensation circuits.On this basis,the source of heat loss in the magnetic coupling mechanism and the heat transfer methods involved in the heat dissipation process are analyzed,which provides a necessary theoretical basis for the subsequent implementation of the thermal characteristics analysis and optimization of the magnetic coupling mechanism.Secondly,an analytical model of the solid round conductor coil is established,and the traditional analytical model is effectively improved by introducing the proximity effect factor.The improved analytical formula is used to homogenize the finite element model,and the complex multi-turn coil model is simplified into a toroidal block model,which reduces the finite element simulation time and improves the simulation efficiency.Using the equivalent idea of a solid round conductor,the Litz coil is homogenized,and the unsimulated Litz coil is simplified into a toroidal block model,which provides a convenient way for the subsequent thermal simulation.Subsequently,the magnetic coupling mechanism of the 1 k W smart robot wireless charging system was simulated by the homogenization method,and the correctness of the simulation process and simulation results was verified by setting up an experimental platform.This method is used to analyze the thermal characteristics of the magnetic coupling mechanism under four typical conditions with or without a magnetic core,different offset distances,different transmission distances,and foreign objects.Finally,the structure of the model was optimized.The coil and the magnetic core were optimized with the goal of maximum transmission efficiency and coil anti-offset ability.The performance of the optimized magnetic coupling mechanism was significantly improved.In addition,we analyzed whether there is aluminum plate in the optimized model,and found that the addition of aluminum plate can effectively prevent magnetic leakage while increasing the loss of the coupling mechanism,leading to a rise in temperature.