Design Of A High Power Density And Miniaturized Wireless Charging System For UAV

This subject takes the wireless charging of UAV as the research background,and aims to solve the problems of large size,heavy mass and poor versatility of the coupling mechanism in the research of the existing wireless charging system of drones,and propose a wireless charging system module with high power density Design method.On the basis of completing a single set of system design,a wide range of charging power levels can be adapted through multiple modules in parallel.First of all,this article designs the overall scheme of a wireless charging system suitable for UAVs based on the subject index requirements.From the perspective of simple control and miniaturization,a single-tube inverter circuit is selected as the high-frequency excitation.Several commonly used resonance compensation topologies are analyzed,and the P-P type structure is selected as the system compensation topology.The influence of mutual inductance,coil internal resistance and load size on the system efficiency is analyzed,and the parameters of the magnetic coupling mechanism are given from the perspective of maximum efficiency.Secondly,several types of coupling mechanisms suitable for UAVs were compared and analyzed,and the plane rectangular coil structure without magnetic core at the receiving end was preliminarily designed.The overall modeling method is used to analyze the influence of the UAV fuselage on the performance of the magnetic coupling mechanism.From the perspective of magnetic core optimization,the arrangement of ferrite cores commonly used in wireless charging is analyzed,and the selection of magnetic materials is further optimized,and designed a high-power density magnetic coupling mechanism suitable for UAVs.The arrangement spacing of the multi-coil matrix is analyzed to minimize cross-coupling.Then,on the basis of summarizing and analyzing the lithium battery charging demand and wireless charging control strategy,the Buck circuit is selected as the power converter at the receiving end.Based on the average current control method,the PI compensation parameters of the voltage outer loop and the current inner loop are designed,and the simulation verifies the output characteristics of constant current and constant voltage.On this basis,the master-slave control method of single-voltage outer loop and multi-current inner loop is selected to complete the current-sharing control of multi-module parallel operation,and realize the wide range of requirements for the charging power level of the drone.Finally,on the basis of sufficient theoretical analysis and simulation research,the production of the principle prototype and the construction of the experimental system are completed.Relevant experimental tests and research are carried out from the aspects of system output power,efficiency,loss of each part,and multi-module parallel connection.The results show that a single wireless charging system has the transmission characteristics of 30 W power and 82.8% efficiency,and the power density of the receiving system is 1.07W/g.When two sets of modules work in parallel,the output current is basically the same,and the system transmission power can be increased to a maximum of 67W.