Research On LCL Resonant Inductively Coupled Power Transfer System

Inductively coupled power transfer (ICPT) system can realize powertransmission with no electrical connections, improving the flexibility ofpower transmission, which is suitable for use in some special occasions,such as underwater, coalmine and bio-medicine, etc. ICPT technologyhad achieved success in the electronic products and rail transportation. Inrecent years, more and more scholars across the world paid attention toICPT technology for its huge economic benefits and broad applicationprospect. The study on ICPT technology in this paper included thefollowing aspects.Firstly, the application of inductively coupled power transfertechnology was introduced, with emphasis on the characteristics of ICPTtechnology. Further, the status quo of study on ICPT technology in recentyears, at home and abroad, was illustrated. The important problemsexisting in an ICPT system were analyzed, and the main content of thestudy was introduced.The paper briefly described the composition and principles oftraditional ICPT system, two kinds of common ICPT type and four methods of basic compensation topology. By analyzing the stability of thesystem, stable boundary conditions of four basic topologies wereinvestigated and put forward the control theory for the stability of ICPTsystem.In order to improve the stability of the traditional ICPT system, anew ICPT system based on resonant network was proposed. Theequivalent model of the entire system was analyzed by the fundamentalwave analysis method. The resonant component method of parametersand design w as proposed. The characteristic curves of ICPT systemunder different operating frequency were derived. It was concluded thatthe LCL resonant ICPT system had advantages of constant voltage outputand high power frequency.In order to determine the specific parameters of the ICPT system,relation curves of quality factor and the coupling coefficient on theresonant component stress were analyzed under different operatingfrequency. With theoretical analysis, it was concluded that resonant-typeICPT system based on LCL had advantages such as lower switchcomponent current stress and higher reliability under the same powerlevel. It laid a solid foundation for the application of ICPT system inhigh-power occasions.Then, a series of experiments were conducted on ICPT system.Firstly, the compositions of the experimental device were analyzed. Secondly, the main circuit, hardware circuit and software of the controlsystem were designed. Lastly, the experimental prototype correctness wasset to prove the correctness of the theoretical derivation. From theexperiment results, the LCL-based resonant ICPT is much more efficientcomparing with the traditional ICPT system.Finally, a summary of all the work was made, and the researchdirection in the future was pointed out.