Research On Modeling And Optimization Of Coils For Wireless Power Transfer Systems

Wireless Power Transfer(WPT)technology can realize non-contact power transfer,thus reducing the trouble caused by traditional wired transmission.Magnetically coupled resonant WPT(MCRWPT)is one of the commonly used WPT means.At present,the MCRWPT technology still suffers from low power transfer efficiency(PTE)and poor adaptability.In this paper,the modeling of the coupling coils is studied.Based on these studies,the efficiency and adaptability of WPT systems are optimized.Firstly,the research status of WPT technology is introduced.Four kinds of compensation network structures and coiresponding PTEs are analyzed.Secondly,in order to cater to the energizing requirement for implantated neural recording system,a wireless power supply platform is designed.A three-phase three-layer coil array is used as the transmiter which can generate an omnidirectional uniform magnetic field in the target area and provide power for all implanted devices in the cortex at the same time.The size of the transmitting coil unit is optimized to improve the magnetic field for the worst case,which is verified by HFSS simulations.For the receiver,a RLC analytical modeling of spiral coils with tubular magnetic core is established.The accuracy of the modeling is verified by HFSS simulation and experimental results in beef tissue.Thirdly,for the application of tumor thermotherapy,a bio-compatibile metal ring is used to replace the magnetic particles inside the target area.In order to improve the induction heating efficiency,the geometries of the transmitting and receiving coils and the working frequency are optimized.COMSOL Multiphysics and HFSS simulation results verifies the effectiveness of improving the heating efficiency.Fourthly,for the PCB coils which is commonly used in WPT for consumer electronics,a RLC analytical model is established up to the self-resonant frequency range.Specially,the skin effect,proxiaity effect,and self-resonant frequency are studied.The analytical model can provide guidance for rapid design and optimization for WPT which is verified by simulation and experiment as well.Finally,a two-dimensional transmitting coil is designed for generating uniform magnetic field facing to the application of wirelss charging platform in consumer elecfronics.The simulation and experimental results show that the magnetic field uniformity effect of this scheme is better than that of the conventional transmitting coil design.