Research On High Power Density Wireless Power Transfer System

Wireless Power Transfer(WPT)has been widely studied for its convenience,aesthetics and safety,but its low power density has affected its applications in aerospace,industrial production and medical industries.This topic will study the design method of high power density WPT system prototype,and develop a high power density WPT prototype.Firstly,the basic structure and working principle of WPT system are analyzed.The mathematical model of inductive WPT system is established by using mutual inductance model.The output power of series-series(SS)and series-parallel(SP)compensating topology system is obtained.And efficiency expression,based on the requirements of the index,design compensation network topology,impedance matching circuit topology and system installation structure,etc.,to complete the overall scheme of high power density WPT prototype.Secondly,the high power density magnetic coupling structure is studied to improve the WPT prototype power density.The characteristics of the WPT system are analyzed,and it is proved that improving the mutual inductance of the magnetic coupling structure can effectively improve the transmission efficiency and achieve the goal of increasing the power density.A convex magnetic coupling structure is proposed for the remaining space of the existing flat magnetic coupling structure.The two kinds of magnetic coupling structure mutual inductance models are obtained by the eigenfunction expansion method.The comparative analysis shows that the convex magnetic coupling structure has greater mutual inductance.The simulation and experiments show that the convex magnetic core has higher mutual inductance,which can effectively improve the system transmission efficiency..Thirdly,in order to improve the system control performance without increasing the volume of the WPT system,a primary and secondary autonomous control strategy is proposed.The system small-signal mathematical model is established,and the system transfer function is reduced and processed.The MCP-PID method is used to design the PI controller parameters.The simulation and experiments show that the designed controller has better dynamic performance and verifies the original secondary autonomy.The feasibility of the control strategy.Finally,according to the requirements of the index,the WPT prototype shielding layer is designed to achieve electromagnetic isolation,calculate the heat dissipation power and design the main circuit heat sink to ensure the long-term stable and reliable operation of the system.Based on the above research,the high power density WPT system prototype development work is completed,and the experimental verification prototype is completed.Meet the requirements of the indicator and obtain a higher power density of the WPT system.