Study On Coupling Method And Effectiveness Of Electromagnetic Induction Charging Of Electric Vehicle

With the shortage of Energy and the degradation of Environment, People become morecare about environment protection, energy-saving and low-carbon economy. Because of thesuperiority of electric vehicle on environment, it has been developed rapidly. The research oninductive charging for electric vehicles will be the new trend in the near future. Comparedwith the normal charging system, the inductive charging is safe, for example, you can avoidthe risk of electric shock even in the rain and bad weather. Furthermore, it is far moreconvenient for charging.This paper describes the development of inductive charging technology at home andabroad, discusses the main topology of inverter and the control methods, and then determinesthe framework of the system and control strategy.Aiming at the special structure of inductive charging system, the paper designs theloosely coupled transformer, and explores the influence of the air gap and the winding way onthe transformer by ANSOFT. The mathematical model of magnetic reluctance circuit isproposed for the EE-shape transformer combined with the distribution of the magnetic fluxline and the effect of cross-sectional area on the coupling coefficient is researched. Also, thegeometric parameters of the transformer are optimized by means of orthogonal experiment.Then discussing the way to improve the transmission efficiency of the loosely coupledtransformer, the usual way is capacitor compensation strategy. By comparing severalcompensation ways in MATLAB/SIMULINK, it is showed that Series-Parallel topology (SP)is the most suitable way for this system and it can improve the output voltage and power.According to the above results, the paper analyzes the influence of operating frequency, theair gap and the load on the output voltage, and it is revealed that the output voltage will be inthe peak when it works at the resonance frequency. As the system will work at hightransmission efficiency when it works at the resonance frequency, we should adjust the workfrequency. By adding a Phase Locked Loop (PLL) on the control model in MATLAB/SIMU-LINK, the primary current and voltage can work in the same phase.Finally, the experiments were carried out for the induction charging system in this paper, it obtained the effects of air gap and cross sectional-area on self-inductance, mutualinductance and the coupling coefficient. In a word, the most suitable way of capacitorcompensation for the system is SP.