| Inductive power transfer(IPT)technology solves the problems of wear,sparks and leakage in traditional wired charging technology,and has the characteristics of safety and reliability,simple operation and easy expansion.However,the carrier of IPT technology is a coil.When the coil is not aligned,the transmission efficiency of the system decreases,which becomes an important factor restricting the development of IPT technology.This paper takes the improvement of the transmission efficiency of the IPT system as the starting point,and studies the design and optimization of the IPT magnetic coupling mechanism.The main research contents of this paper are as follows:(1)In terms of IPT system theory,a mutual inductance coupling model of the IPT system is established,the coupling relationship between the transmitting coil and the receiving coil is analyzed,and the impact of the offset distance on the transmission efficiency of the IPT system is studied.A method to improve the transmission efficiency of the IPT system is given.The magnetic circuit models of densely wound coils and DD coils are established.Aiming at the problem that the efficiency of the wireless power transmission coil is reduced due to the offset,a double-layer overlapping coil structure is proposed.Based on its two-dimensional magnetic field analysis,the equivalent magnetic circuit model of the double-layer overlapping coil is established,and the influence of IPT is analyzed.The factor of the anti-offset ability of the system provides theoretical support for the design of the magnetic core.(2)In terms of wireless power transmission coil structure design,simulation models of densely wound coils and DD coils are established,and the anti-offset characteristics of densely wound coils and DD coils are analyzed.The influence of the structural parameters of the double-layer overlapping coils on the transmission characteristics of the system is mainly analyzed,and the structural parameters are optimized.Simulation and experimental results show that the proposed double-layer overlapping coil structure has the characteristics of power supply in multiple charging areas,which can not only charge multiple loads at the same time,but also maintain high efficiency charging when the receiving coil is laterally shifted.(3)In terms of magnetic core structure design,in order to improve the transmission efficiency of the IPT system,a staggered magnetic core structure is designed based on the double-layer overlapping coil geometry.A rectangular core IPT system and a strip core IPT system simulation model were built in the finite element software.The simulation results verify that the strip core improves the efficiency of the IPT system better than the rectangular core.The structural parameters of the staggered magnetic core are optimized.In order to improve the coupling coefficient of the system,the thickness of the staggered magnetic core can be appropriately reduced and the width of the staggered magnetic core can be increased.A test platform was built to verify that the staggered cores are better than rectangular cores in improving system efficiency.(4)In terms of the application of double-layer overlapping coil magnetic coupling mechanism,the overall structure of the automatic guided vehicle(AGV)wireless charging system was first designed,and the hardware part was designed,including the high-frequency inverter circuit,Resonance compensation circuit and rectifier circuit;Then the AGV wireless charging system software is designed,and the SPWM control flow chart is given.Finally,the AGV wireless charging system test device is built.The test results show that the AGV wireless charging system maintains a high efficiency power supply,Verifying the rationality of the design of the magnetic coupling mechanism with double-layer overlapping coils. |
PDF Full Text Request