| At present,Wireless Power Transmission(WPT)technology has been widely used in daily life.This technology has the characteristics of high safety factor and portability.However,most WPT systems can only satisfy load-independent Constant Current(CC)or Constant Voltage(CV)output,and it is difficult to adapt to the frequent connection and removal of charging equipment,and it is even more difficult to provide multiple independent working power transfer path.Therefore,this paper proposes a loadindependent coplanar multi-branch constant current and constant voltage wireless power transmission system.Double-layer high-permeability ferrite dielectric blocks are added at the intersection of adjacent coplanar coils.Improves coupling between adjacent coils.Add more branches to the system to verify that the multi-branch structure can still maintain the constant current and constant voltage output characteristics,and further analyze the upper limit of branches that the system can carry,the rules of branch chain expansion,and the key parameters that affect the number of chain expansion nodes.The main content and achievements of this paper are as follows:(1)First,design the multi-branch WPT structure,and use Maxwell 3D software to scan the parameters of the coplanar multi-branch WPT system before and after adding double-layer ferrite to determine the best parameter configuration;Secondly,establish a matrix for the multi-branch system through circuit analysis theory,and analyze Constant current and constant voltage characteristics;then give the rules for different branch chain expansion: To expand a constant voltage section requires two relay resonators and a constant voltage receiving end;To expand a constant current section requires a relay resonator And a constant current receiving end;Then bring in the actual measurement parameters,and use the ADS software to simulate and verify the output characteristics of the load-independent constant current(CC)and constant voltage(CV)of the multi-branch structure.(2)First,build the experimental platform of the three-branch WPT system,and verify that the multi-branch structure can maintain good Constant Voltage and Constant Current characteristics within the load dynamic range,and the maximum PTE of the system is 90.7%;When the three-branches are converted to two-branches,the maximum PTE of the system is 91.7%;And then a four-branch WPT platform is built to verify that each branch can work independently and be designed independently,and the maximum PTE of the system reaches 88.73%;Finally,compare the three-branch and the four-branch efficiency change curve,the error between the measured value and the theoretical value,the change of the coupling coefficient between the shared relay coil and the adjacent coil,combined with the spatial distribution of the coils and the arrangement of the ferrite,prove that in the multi-branch WPT system proposed in this paper,the maximum number of branches in the system is four.(3)Build a constant voltage branch and constant current branch chain expansion system.The maximum PTE of the constant current branch chain expansion system can reach 88.71%.By analyzing the change of the coupling coefficient on the transmission path of the constant current section,it is obtained that the number of charging sections in the branch chain expansion is related to the main coupling on the power transmission path.Finally,the Some design to boot. |
