Study On Hybrid Ipt Systems With High-misalignment Tolerance For Constant-current And Constant-voltage Outputs

Wireless power transfer technology has been widely applied in consumer electronics,underwater power supplies,biomedical implanted devices and electric vehicles(EVs),etc.because of its significant advantages such as safety,high reliability,and enough flexibility.Inductive Power Transfer(IPT)has become a research hotspot of domestic and foreign scholars because of its wide application range among WPT.In the process of IPT charging,it is always necessary for the system to provide constant current(CC)and constant voltage(CV)to variable loads,and the physical misalignment between the primary winding and the secondary winding is inevitable,so that output power of the system will reduce and loss of the system will increase.Therefore,it is very important to study the inductive power transfer system with high-misalignment for constant current and constant voltage output.In order to ensure constant current and constant voltage output of the IPT system when the load changes and the magnetic couplers are misalignment at the same time,and reduce the difficulty of the control with the IPT system,this paper firstly studies the S-S and CLC-CLC compensation topology circuits both of which have the characteristic of constant current output,but the output current of the latter is inverse proportional to the mutual inductance,which is different from that the output current of the former is proportional to the mutual inductance.According to the above analysis,Based on the characteristics of the Series-Series(S-S)compensation topology and the CLC-CLC compensation topology,and by adding alternating current(AC)switches and compensation components to the secondary circuit,A hybrid IPT system for constant current and constant voltage outputs is proposed in this paper.And by analyzing the constant current mode and constant voltage mode of the hybrid IPT system,and misalignment characteristics of the double-D quadrature(DDQ)pad,DDQ pad is selected as the magnetic coupler of the hybrid IPT system.After that,this paper studies the parameter optimization methods of the hybrid IPT system in the constant current mode and constant voltage mode,thereby laying a solid theoretical foundation for realizing high misalignment tolerance for constant current and constant voltage outputs of the hybrid IPT system.Finally,in order to verify the correctness and feasibility of the proposed hybrid IPT system with high misalignment tolerance for constant current and constant voltage outputs,this paper builds a 1k W experimental device for experiments to investigate the IPT system with high-misalignment tolerance for constant current and constant voltage outputs.The experimental results demonstrate that in the constant current mode,the output current variation of the IPT system can be constricted within 5% with the load varying from 50Ω to100Ω when the pickup misaligned from-212.5mm to 212.5mm along the x-axis and-48 mm to 35 mm along the z-axis.The overall system efficiency changes from 90.20% to 95.81% with the predetermined misalignment range and load variations.And in the constant voltage mode,the output current variation of the IPT system can be constricted within 5% with the load varying from 100Ω to 1000Ω when the pickup misaligned from-212.5mm to 212.5mm along the x-axis and-48 mm to 35 mm along the z-axis.The overall system efficiency changes from78.54% to 94.68% with the predetermined misalignment range and load variations.The above results verify the hybrid IPT system is effective and feasible.In addition,the hybrid IPT system does not require complex negative feedback control schemes,and can avoid reactive power input,and can limit the inverter output current when the pickup moves out of the operating area.