Research On Inductively Coupled Wireless Power Supply Technology With Perturbation Force

Inductively coupled wireless power supply is a technology that employs the principle of electromagnetic induction and combines high power electronics technology and magnetic field coupling technology to realize high power and high efficiency of wireless power transmission over medium and short distances.It has the advantages of safety,convenience,easy maintenance,high reliability and strong environmental adaptability,and boasts bright application prospect.In the inductively coupled wireless power supply system,the power,efficiency and distance of power transmission are limited due to the loose coupling characteristics of the primary and secondary sides of the coupler.To address this problem,scholars at home and abroad have carried out a lot of theoretical and experimental research.The research found:(1)The low coupling coefficient limits the efficiency of power transmission;(2)Leakage inductance greatly limits the maximum power of electric energy transmission;(3)The change of the coupling position causes the resonance point to shift,which affects the compensation effect,thereby leading to the reduction of output power and efficiency.However,the current research focuses on independent optimization of power or efficiency indicators,and research on synchronous optimization of power and efficiency has yet to be improved.In addition,the current research on inductive coupled wireless power supply system mostly does not consider the electromagnetic force of coupler,nor does it consider the influence of power and distance of electric energy transmission on electromagnetic force.The existence of electromagnetic force means that although the coupler has achieved structural separation and non-contact,mechanical coupling still exists,which can generate and transmit vibration,limiting the application of inductive coupler wireless power supply technology in precise vibration isolation platforms and so on,this problem has not yet been highlighted and resolved.Focused on the above problems,the following researches have been carried out in this article: Firstly,the mechanism of electromagnetic force generation is considered,and the influence of coupler structure and position change on electromagnetic force is studied.Secondly,the influence of coupler structure on coupling coefficient and leakage inductance is studied.Finally,a new coupled structure and methods of implementation are proposed to synchronously increase the power and efficiency of wireless energy transmission and minimize the effects of electromagnetic forces.The main innovations and contributions of this paper are as follows:1.Establish the mechanical theoretical model of the coupler,and based on the electromagnetic induction theory,analyze the principle of generation of electromagnetic force of the coupler.On the basis of it,the influence of magnetic field strength,induced current magnitude and distance on the ampere force of the secondary coil are analyzed;the influence of magnetic field strength,excitation current magnitude and distance on electromagnetic force of secondary magnetic core are taken into account.The effective way to reduce electromagnetic force is studied.The results show that the magnetic field generated by the excitation unit is geometrically symmetrical and the receiving unit is located at the geometric center of the magnetic field space,which helps weaken the electromagnetic force.The higher the symmetry of the magnetic core structure,the higher the concentricity between the secondary coil and the magnetic core,and the more obvious the effect of weakening the electromagnetic force.In the electric energy wireless transmission experiment,under the same coupling position and power condition,the electromagnetic force can be weakened from 500 mN to less than 100μN.2.The electrical theoretical model of the perturbation coupler is established,and the problems of low coupling coefficient and large leakage inductance of the loosely coupled system are analyzed by the leakage inductance model.On the basis of that,the influence and variation law of coupler structure,displacement variation,coupling coefficient and leakage inductance are analyzed.The effective ways to improve coupling coefficient,reduce leakage inductance and influence coupling coefficient by displacement change are studied.The research results show that the closed magnetic circuit coupler structure has obvious effects on increasing the coupling coefficient and reducing leakage inductance.Under typical conditions,the coupling coefficient is increased to 0.96,the change rate is less than 1%,the leakage inductance is reduced to 95μH,and the change rate is less than 6.5%.3.The loss model of loose coupling transformer is established,the composition of the coupler loss and the key factors that restrict the power and efficiency of the transmission are analyzed.On these basis,the leakage inductance compensation model of the coupler is analyzed,and the effective ways to reduce loss and improve the power and efficiency of the transmission are studied.The results of research mirrors that the copper loss and magnetic loss of the coupler can be effectively reduced by optimizing the design;the transmission power and efficiency can be effectively improved by the method of resonance compensation.In a typical 200 W experiment,the efficiency of the transmission link can reach 90% and the efficiency of the whole machine can reach 85%,which verifies the feasibility of the method.The results of research in this paper can be directly applied to the basic theoretical research of electromagnetic force decoupling in the field of inductively coupled wireless power supply technology,which indirectly supports the testing and research and development of the perturbation force coupling wireless power supply system,and then promotes the application of technology in vibration isolation platforms and other occasions.