Design Of Coupling Mechanism Of Omnidirectional Wireless Power Transfer System Based On Magnetically Coupled Resonance

The wireless power transfer technology makes energy transmission free from the shackles of wires to a certain extent.Compared with traditional cable transmission technology it has the advantages of safety,convenience.And omnidirectional wireless power transfer is a further expansion of the scope of application of wireless power transfer.The main work of this paper is to design the coupling mechanism of omnidirectional wireless power transfer system.Based on the technology of magnetic coupling resonance,the distribution of magnetic field in the transmitting mechanism and the uniformity of energy picked up by the receiving mechanism are discussed.The performance of smoothing pick-up power of the coupling mechanism designed in this paper is verified by drawing simulation model and designing experimental platform.The main work of this paper are as follows:(1)This paper describes the theoretical basis,historical background and development and application of wireless power transfer technology,introduces four main wireless energy transmission technologies: ultrasonic transmission,electromagnetic radiation transmission,electric field coupling transmission and magnetic field coupling transmission,and briefly describes their technical characteristics.This paper analyses the problems of the coupling mechanism with one degree of freedom in common use,points out the advantages of using omnidirectional wireless energy transmission,and discusses the current situation and development of omnidirectional wireless power transfer system and the main coupling mechanisms of omnidirectional wireless power transfer system proposed at present,and explains the characteristics of these schemes in the design of coupling mechanism,circuit topology and control system.Through the analysis and comparison of two main multi-degree-of-freedom coupling mechanisms,the design objectives of this paper are put forward.(2)This paper compares the modeling and analysis methods of the magnetically coupled resonance wireless power transfer system.In the three methods of coupled mode theory modeling,Scattering parameters theory modeling and circuit theory modeling,the circuit theory is selected to model the magnetically coupled resonance wireless power transfer system.Then the magnetically coupled resonance wireless power transfer system is introduced in modules.The relationship between parameters of resonant circuit is analyzed emphatically.(3)In this paper,the calculation method of inductance,capacitance and resistance of arbitrary coil at a certain frequency is explained theoretically.The coupling mechanism of omnidirectional wireless power transmission is designed.The main design goal of the launching mechanism is to form a uniform magnetic field.The problems in the design of the transmitting mechanism in some schemes are explained through theoretical analysis.To solve these problems,the design method of this paper is put forward.The design is mainly based on the characteristics of polyhedron and the application of Euler circuit.The main design goal of the receiving mechanism is to achieve uniform coupling energy.In this paper,an evaluation method of power pick-up uniformity is proposed,and the pick-up power uniformity of several common receiving mechanisms is compared.The model of launching mechanism is simulated by Maxwell software,and its magnetic field distribution is displayed by three-dimensional distribution map.An experimental platform is built to verify the smoothness of power pickup of coupling mechanism,which proves the feasibility of the coupling mechanism of omnidirectional wireless energy transmission system designed in this paper.