| Dynamic wireless power supply technology is widely used in the field of electric vehicles,which can greatly increase the driving range of vehicles and promote the lightweight of vehicles by reducing or even eliminating the need to carry batteries.In the current dynamic wireless supply system,the transmitter generally adopts the segmented conductive structure,which has the advantages of high power efficiency and low magnetic field leakage compared with the early long guide rail structure.However,in the process of power supply for electric vehicles in dynamic wireless supply system,transmission power fluctuation caused by transmitter switching,dislocation of electromagnetic coupling structure and longitudinal vibration will lead to low power efficiency of the system,decline in electrical quality,and even stop the work of electric body in serious cases.Therefore,this paper studies the power fluctuation caused by the switching of transmitter and the vibration of electromagnetic coupling structure in the dynamic supply process of moving receiver.(1)In this paper,the dual-transmitter/single-receiver electromagnetic coupling system is taken as the minimum dynamic coupling unit,and the efficiency analytical expression in the dynamic coupling system is derived based on the circuit and electromagnetic field theory,and then the variation law of the coupling coefficient that affects the efficiency fluctuation of the system is analyzed under different disturbance scales in three-dimensional space.(2)Under the ideal working condition,the optimal spacing of the adjacent transmitters under the set coil size is determined through the simulation study on the working cycle of the minimum dynamic coupling unit.On the basis of double coil power supply,the optimal interval of double coil power supply is further determined and verified by experiments.(3)In order to obtain load movement and offset position information in real time,the coupling coefficient and power under different coupling angles and transmission distance are firstly analyzed,the fluctuation law of mutual inductance and power is obtained,and the causes of this law are analyzed.Secondly,in order to reduce the influence of longitudinal vibration on the system,a three-cell cross structure is proposed at the receiver.Finally,the simulation and experiment show that the structure can stabilize the output power under the actual disturbance condition.(4)For lateral migration of power fluctuation problem,this paper puts forward four-coil position detection system,and describes its working process in detail,this system can not only realize the real-time positioning function of electric vehicle in the dynamic process,but also interact with the signal of power supply track to provide coil switching command for transmitter. |
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