The Research Of Magnetic Resonance Wireless Power Transmission Technology With PCB Coil

As a leading edge in the field of power transmission around the world,Magnetic resonant wireless power transmission is a way of transferring power via resonance in the near field.The magnetic coupling structure,the key part of magnetic resonance wireless power transmission system,has great impacts on transmission distance and transmission efficiency.Printed Circuit Board(PCB)coil is adopted as the magnetic coupling structure of the system due to its advantages such as,small size,simple fabrication process,low production cost,good consistency of coil parameters.etc.Compared with inductively coupled and microwave wireless power transmission,the magnetic resonance wireless power transmission technology can better solve the problems existing in power supply of the wireless sensor nodes placed at the high voltage side of the medium voltage electrical equipment.The proposed system shows great value in both theoretical and practical fields on account of continuous power transmission from low voltage side to high voltage side with meeting insulation requirement in the mean time.Firstly,the mechanism of magnetic resonance wireless power transmission is analyzed,and the equivalent circuit model is established by using circuit theory.The key factors affecting the transmission efficiency are analyzed while the maximum transmission efficiency is analyzed deeply.The size of the coil structure is greatly limited because of the compact structure of the switch cabinet.Therefore,this paper puts forward a method for the optimal design of PCB coil in the limited space with the aim of maximizing the transfer efficiency.As a result,the quality factor of the coil and the mutual inductance coupling coefficient are greatly improved by adjusting the parameters of the coil,so as to improve the transmission efficiency of the coil structure.This paper studies the influence of the peripheral metal on the magnetic resonance wireless power transmission in depths due to the large quantities of metal in the switch cabinet.Large eddy current loss can be generated by the high frequency magnetic field passing through the perfect conductor.Therefore,in order to improve the transmission efficiency,we use magnetic membrane to reduce the diffusion of high frequency magnetic field in metal.Secondly,the key indicators of prototype,the system solutions,the circuit topology are determined according to the internal structure of the switch cabinet,high and low voltage insulation distance,the power supply of wireless sensor nodes.The magnetic resonance wireless power transmission system is designed according to conclusion of the analysis mentioned above,which includes high frequency power amplifier circuit,AC/DC circuit,and high frequency rectifier regulator circuitFinally,an experimental platform is set up and the conclusion of the relevant theoretical analysis is verified by experiments.A prototype of the magnetic resonance wireless power transmission system based on PCB coil is developed,which takes the on-line monitoring module of the high voltage side as power supply target.The key waveforms and data of the prototype are tested.The waveforms are stable,which indicates the system’s good working state,thus having a great value in promotion and application.