Research On Three-phase Coupling Mechanism For Electric Vehicles Dynamic Wireless Charging

The dynamic wireless charging technology makes electric vehicles be charged without parking,and solves the bottleneck problem of insufficient mileage.In the dynamic wireless charging system,the coupling mechanism is the bridge for energy transmission and directly determines the system's performances.Therefore,the design of a new coupling mechanisma and a reasonable coupling mechanism design method have become the current research hotspot.At the same time,the system's electromagnetic security has become an important issue that needs to be solved urgently.This paper focuses on the three-phase coupling mechanism for EVs' dynamic wireless charging,the main work is as follows:Firstly,in order to solve the shortcomings of the traditional single-phase coupling mechanism with large output power fluctuations,a novel three-phase ?-type coupling mechanism is proposed.Then,the working principle of the pro is theoretically analyzed,and the influence of winding methods and core structure on the system performance is studied by simulations.Based on the AC impedance model,the compensation network suitable for this coupling mechanism is also analyzed.Secondly,the design method of the coupling mechanism is studied.The paper proposes a new design method for the three phase I type coupling mechanism,solves the problem of repeated iteration in the existing design methods and reduces the design workload.Based on this design method,a design example of the three-phase ?-type coupling mechanism is given,and the designed coupling mechanism is checked by simulation and calculation.The results show that the designed coupling mechanism can well meet the requirements of the wireless charging system.Thirdly,the electromagnetic safety of the coupling mechanism is studied.The electromagnetic distribution of the coupling mechanism in free space is revealed.The shielding loss,shielding effectiveness and its effect on the system's performance of the conductive metal material and the magnetic materials are studied through the finite element simulation method.And the effect of the chassis on the electromagnetic security is also analyzed.The research results provide a theoretical basis for the electromagnetic shielding design of the coupling mechanism.Finally,a three-phase ?-type coupling mechanism prototype with a power level of 60 kW is built.The experimental results show that the new coupling mechanism can effectively realize wireless power transfer over a long-distance and has the advantage of stable output power during the dynamic charging process.The experimental result also verifies the analysis of the structural characteristics and compensation network and proves the feasibility of the proposed design method.