Structure Design And Optimization Of Small Power Wireless Charging Transmitter For Electric Vehicle

With the development of wireless charging technology of electronic equipment mobile terminal,the wireless charging of electric vehicle is becoming possible.The wireless charging system of electric vehicle is composed of transmitter,receiver,power box and on-board controller,etc.In daily use,vehicle rolling may cause damage to the coil and inner core of the transmitter,while the heat accumulation generated by the coil work may affect the working efficiency,stability and service life of the transmitter.The purpose of this study is to propose a design method of low-power wireless charging transmitter for pure electric vehicles,and then develop a wireless charging transmitter with the best comprehensive performance.The main contents of this paper are as follows:1)Transmitter design.Based on the existing 2.0kW wireless charging inner core and coil as well as the original transmitter,the initial design of the wireless charging transmitter of electric vehicle is carried out through the structural design and material optimization,which lays the model foundation for the next part of the research.2)Rolling simulation and lightweight design of transmitter.The simulation model of single wheel rolling emitter is established by using the rigid flexible coupling analysis method,and the anti rolling performance of the emitter is evaluated.The topology optimization method is used to carry out the lightweight design of the transmitter,based on which the prototype is made and the rolling experiment is carried out.The research shows that the compression performance of the initial transmitter is improved obviously and meets the strength design requirements,but the overall utilization rate of materials is low;the mass of the transmitter after lightweight is 42.5%lower than that of the initial transmitter;the rolling test results show that the simulation and test results are similar,and the design of wireless charging transmitter meets the design requirements.3)Numerical analysis of temperature field and optimization of heat dissipation.Using4)CFD numerical analysis method,the influence of solar radiation on the temperature field of the transmitter is evaluated and the temperature field of the transmitter is analyzed according to the evaluation results.The heat dissipation effect of different sizes of heat dissipation holes is studied under the condition of natural heat dissipation and forced heat dissipation by adding heat dissipation holes in the outer frame layer of the transmitter.The research shows that the solar radiation has a great influence on the temperature distribution of the transmitter.Compared with the early generation products of the enterprise,the radiation effect of the transmitter has been improved,but the improvement of the radiation effect is not obvious.The average temperature and the maximum temperature of the external surface of the transmitter decrease obviously under the natural heat dissipation state after the increase of the heat dissipation hole.Taking the 80mm long heat dissipation hole as an example,the average temperature of the external surface of the transmitter decreases by 11.8k,with the maximum temperature.The temperature has been reduced by 21.5k,and the heat dissipation effect has been improved obviously;the heat dissipation effect of the transmitter is excellent under the condition of forced heat dissipation,which can provide some reference for the heat dissipation design of the second generation transmitter in the later stage.4)Multi objective optimization based on genetic algorithm.Based on the emitter model with heat sink,a multi-objective function of heat sink,anti rolling performance and lightweight is established based on Matlab genetic algorithm toolbox.The multi-objective structure of the emitter with heat sink is optimized to obtain a transmitter with better comprehensive performance.The simulation analysis of vehicle rolling and numerical analysis of heat dissipation characteristics are carried out to evaluate the reliability and rationality of multi-objective function optimization emitter structure based on genetic algorithm.The research shows that the anti rolling performance of the transmitter after the final multi-objective optimization is improved and the total mass is reduced by 7.43%,which meets the requirements of anti rolling and heat dissipation performance at the same time.