Analysis And Design Of Multi-load Wireless Power Transfer System

As a new type of power transfer,Wireless Power Transfer（WPT）can avoid many drawbacks in the process of power supply with wires,improve the degree of freedom of power supply method,and expand people’s imagination of power transfer method.At present,there are many researches and applications of single-load Wireless Power Transfer,however,however,the analysis and research of multi-load system is relatively few,which has higher research value than single load system.Therefore,based on the lumped parameter theory,this paper analyzes and studies the single-source multi-load system.Firstly,based on coupled-mode theory,this paper expounds the principle of energy transfer in nondestructive oscillation system and analyzes the process of energy transfer in Magnetic Coupled Resonant-Wireless Power Transfer（MCR-WPT）.And based on the circuit principle,the expression of the power and efficiency of the system transfer is deduced,the transmission models of two-coil structure and four-coil structure are established,the influence of coil quality factor,and frequency and coupling coefficient on the transfer characteristics of the system is studied.Secondly,based on the principle of equivalent circuit,the load conditions for maximizing the transfer efficiency of WPT are analyzed.In view of the influence of loads with different properties,this paper studies the influence of various parameters on the transfer efficiency of the system when the loads are resistive,inductive and capacitive.The reasons of transmission efficiency decline when the load is inductive and capacitive are summarized in detail,and the load compensation scheme is put forward accordingly,which improves the transmission efficiency of the system.The reasons for the decline of transfer efficiency when the load is inductive and capacitive are summarized in detail,and the load compensation scheme is put forward accordingly,thus improving the transmission efficiency of the system.Finally,this paper analyzes the influence of multiple loads on the transfer characteristics of MCR-WPT system,which is the core chapter.A3 D three-load coil model is established by using electromagnetic field finite element software Maxwell.Based on the circuit principle,the theoretical knowledge of single-load,double-load and multi-load systems is expounded,the transmission power under the condition of multi-load coils is studied in detail,and the optimal load resistance and transverse as well as longitudinal transmission distance under the condition of the model parameters are found,and the reasons of frequency splitting and the suppression methods are explained,and the above researches are verified by experiments.