Passivity-based Control For Dynamic Wireless Power Transfer System In Electric Vehicles

With the advantages of zero emission and low noise,electric vehicles are widely used in the world.However,the charging technology used in the life generally has the phenomena of fixed charging position and long charging time,which leads to serious problem,i.e.range anxiety,and limits the rapid development of electric vehicles.In order to solve the above problems,this paper designs a dynamic wireless power transfer(DWPT)system of electric vehicle,aiming at enhancing the dynamic performance and improving power transmission of the system.The main research work is as follows:The overall structure of DWPT system is designed.Double-layer core structure is adopted to make the distribution of magnetic density and temperature field more uniform.The working principle of double-sided LCC resonant compensation network is studied from the perspective of fundamental frequency component and high frequency component.The charging characteristic of battery load in DWPT system is analyzed,and the mathematical description of each charging stage is given.The Buck converter is selected as the back of DWPT system,and the corresponding control strategy is made to improve the power transmission of the system.The whole dynamic model of DWPT system with double transmitter is established.By using the state space averaging(SSA)theory,the whole system model of DC / DC converter in open state and off state is established respectively,and then the two states are integrated to get the complete dynamic mathematical model of the system.A passivity-based control(PBC)strategy is proposed.In order to reduce the impact of disturbance in DWPT system,nonlinear disturbance observer(NDO)is introduced to combine with the PBC controller,thus improve the accuracy and robustness of the controller.The DWPT system is tested and analyzed by simulation and experiment.It is verified that the PBC-NDO controller can ensure the smooth output voltage and no steady-state error at different simulated speeds of electric vehicle.Compared with the traditional PID control,the PBC-NDO control has a very fast regulation speed and strong anti-interference performance,and its dynamic performance is far better.