Research On Against Misalignment Inductive Power Transmission System Based On Combined Design Of Topology And Coupler

In many application fields of the inductive power transfer(IPT)system,the misalignment of the coupling mechanism is unavoidable.However,the misalignment of the coil will cause the coupling coefficient to change,which will lead to the instability of the system output power and affect the reliability and security of the system.In order to achieve stable output power,it is of great significance to design an IPT system with high misalignment tolerant ability.At present,for the purpose of simplifying the control complexity of IPT systems,the main ways to improve the misalignment tolerant ability of the system are compensation topology design or the coupling pad design.However,using any one of the above design methods to improve the system’s the misalignment tolerant ability is limited.Therefore,this thesis proposes a design method combining compensation topology and the coupling pad,which can better solve the power fluctuation problem of the IPT system when the coupling mechanism has a large-scale misalignment.This thesis firstly analyzes and summarizes the output power and system AC efficiency of the SS compensation topology in four compensation states,and selects the detuning primary side and fully compensated secondary side with the misalignment tolerant ability and system AC efficiency independent of the degree of detuning.At the same time,in order to achieve high system efficiency and ensure soft-switching of the high-frequency inverter circuit switch tube,it is necessary to use the capacitor undercompensation method for primary side detuning,that is,the primary side detuning rate takes a positive value.Secondly,the misalignment tolerant ability of common coil structures under the same size is analyzed by the finite element simulation software Maxwell.Based on the idea of constructing a uniform magnetic field based on the principle of mutual inductance cancellation,the square coil with the best anti-offset ability is selected to combine with the "tian"-shaped coil with strong reverse mutual inductance,and a new "fang + tian" coil structure with the high misalignment tolerant ability is proposed,and the structure has good applicability.Finally,a new type of the compensation topology and the coupling pad composite IPT system are constructed by combining the SS topology of the detuning primary side and fully compensated secondary side with the "fang + tian" coil structure.The parameters of the SS topology with the detuning primary side and fully compensated secondary side are designed,and the primary side detuning rate and the change rate of the coupling coefficient under the minimum fluctuation of the output power are obtained,and the "fang + tian" coil structure is optimized by using its coupling coefficient change rate,.so that the composite IPT system has the misalignment tolerant characteristics.In addition,the effectiveness of the proposed method is verified by building a 1.8-k W composite IPT system principle prototype.The experiment results show that the IPT system can tolerate-220mm～+220mm X-misalignment,-220mm～+220mm Y-misalignment(55% of the maximum coil size),the output power fluctuation is less than 5%,and the system efficiency is always higher than 90.0%,and the peak efficiency reaches 92.4%.