Research Of Wireless Power Transfer System On Magnetically Coupled Full-bridge LCCL Resonance

With the growth of social economy and the improvement of power electronics technology theory,the extensive application of consumer electronics products and industrial electrical equipment are improving people's life.Wireless Power Transfer(WPT)technology,which is different from the traditional wire power supply methods and has high security,good electrical isolation and low maintenance cost,provides great convenience for people's life,and has wide application prospects in mobile phones,electric vehicles and implantable medical equipment.At present,as one of the research directions of WPT technology,magnetically coupled resonant WPT technology has the characteristics of medium distance transmission,strong migration resistance and high transmission efficiency.However,the change of coil distance,offset and load will cause the sudden change of output voltage and the decrease of efficiency of WPT system.Therefore,it is of great engineering significance and value to explore and develop an stable and high efficient magnetically coupled resonant WPT system.Firstly,this paper briefly describes the background and significance of WPT technology research,and introduces the basic classification of WPT technology and gives their respective advantages and disadvantages comparison.On this basis,it also analyses the research status of magnetically coupled resonance WPT system at home and abroad,and summarizes the current development trend and key technologies of magnetically coupled resonance WPT system.Secondly,on the basis of introducing the high frequency power topology and compensation networks of the magnetically coupled resonant WPT system,the working principle of the magnetically coupled full-bridge LCCL resonance WPT system is analyzed in detail.After comparing the modeling theory of coupled mode theory and circuit theory,the optimal operating frequency derivation process of the transmitter with the characteristics of constant power transmission and ZPA and soft switching is given concretely by using the circuit theory.Thirdly,the optimal efficiency transmission characteristics of the magnetically coupled full-bridge LCCL resonance WPT system are analyzed at the optimal operatingfrequency.In addition,the transmission characteristics of the WPT system under the change of resonant inductance,coupling coefficient and load are analyzed in detail,and the corresponding MATLAB simulation results are given to verify the feasibility of theoretical analysis of the WPT system.Then,using TMS320F28035 as the control core of magnetically coupled full-bridge LCCL resonance WPT system,the design and selection of LCCL resonance compensation network parameters,coil and main circuit power devices and the design of DSP control circuit are introduced in detail,and the software program flow and the configuration of DSP registers are given in detail.Finally,a WPT experimental prototype with 300 W transmission power is built.After analyzing the simulation results of Saber circuit,the experiment further verifies the optimal operating frequency of the prototype.The soft switching waveforms of power devices and the transmission efficiency curves are compared under different loads.On the other hand,the key waveforms and data of constant power output at transmitter and constant voltage output at receiver are also tested.The experimental results verify the feasibility of the experimental prototype design and theoretical analysis of the system.