Research And Simulation Of High Efficiency Resonance Transform Technology In IPT System

Wireless power transmission technology makes power transmission free from various cables and sockets.It has been used in many fields of life.The most common and mature among various wireless energy transmission technologies is electromagnetic induction type wireless energy transmission(Inductive).Power Transfer,referred to as IPT)technology.Electromagnetic induction type radio energy transmission technology is based on the principle of electromagnetic induction to realize wireless energy transmission.It is safe,reliable,flexible and convenient.It has been applied in electric vehicles,household appliances and small electronic products.The LCC resonant converter combines the advantages of a series resonant converter and a parallel resonant converter,and enables the high frequency inverter of the IPT system to operate in a soft switching state.This paper mainly studies the LCC resonant converter applied to IPT system,analyzes the functional principle of LCC resonant converter,establishes mathematical model and determines the main parameters of the system by fundamental analysis.The electrical characteristics of the LCC resonant converter are simulated by MATLAB software,and the conditions for maintaining the efficient operation of the IPT system are proposed.The load change of the IPT system will cause the reflected impedance of the energy transmitting end to change,which in turn causes the resonant frequency of the LCC resonant converter to change.When the resonant frequency of the LCC resonant converter shifts,it will cause the power factor in the IPT system to decrease and even the high frequency inverter loses the soft switching function.In turn,the switching loss of the high-frequency inverter in the IPT system is large,the equipment is damaged,and the system efficiency is also reduced.This paper proposes a variable capacitance control strategy that overcomes the shortcomings of fixed frequency phase shifting and variable frequency resonant control strategies.By adding a variable capacitor group to the LCC resonant converter to adjust the resonant frequency of the system,the problem of the system resonance frequency deviation when the reflected impedance of the energy transmitting end of the IPT system is changed is solved,so that the resonant frequency of the LCC resonant circuit is close to the high frequency inverse.The operating frequency of the transformer maintains a weak sensibility.Moreover,the IPT system can realize the soft switching function of the high frequency inverter switching tube within a wide range of reflection impedance variation,and reduce switching loss and switching stress.In addition,a Boost+LCC resonant converter structure is designed,and the output voltage of the LCC resonant converter can be stabilized by adjusting the duty ratio through the front-end Boost circuit.The feasibility of the variable capacitance control strategy is verified by MATLAB/Simulink software simulation experiments.