Research On Coupling State And Transfer Characteristic Of Magnetic Resonant Wireless Power Transfer System

As a new development of wireless power transmission technology,wireless pow-er transfer via coupled magnetic resonances has many merits:delivering much more power with longer ranges and higher system efficiency,non-radiative,penetrability,it has became one of the hot spot researches by domestic and international schol-ars.The progress of technology in the field of wireless power transfer via coupled magnetic resonances is remarkable in the last few years,but there are also many questions are unsolved,such as transfer theory research,comprehensive optimiza-tion of transfer distance and transfer efficiency,the analysis method of transporting mechanism is comparatively simple,which need systemic and in-depth theoretical study.In order to solve these questions,firstly,we built the normal mode model of resonance circuit resonant system,make coupling analysis with resonant system and incident energy,so we could got that the resonant system loss and overflow power by incident energy are the two key factors of the coupling state.The analysis method of magnetic resonant wireless power transfer system cou-pling state which based on incident energy analysis of resonant system was presented,on account of the power transfer law and the system construction,we extend the single resonant system to the coupling analysis of total system,we could got that the system loss and the overflow power by incident energy axe the two key factors of the coupling state.We extend the zero input system loss analysis by coupled mode theory into system loss with consecutive input.We got the conclusion that system loss has composite affect with system coupling state and transfer efficiency.A new measuring method of the electromagnetic coupling efficiency which is based on scattering matrix was presented.The electromagnetic coupling efficien-cy model was deduced through system circuit model and two port network model,system electromagnetic coupling efficiency was got by scattering parameter,this method could provide a new thinking of high frequency electricity parameter mea-surement.Make research for the harmonic compensation circuit model of WPT system,make research for the effect of the coupling coefficient and secondary quality factor with voltage gain and current gain and transfer efficiency.Make a decision that PSSS compensation structure is the best one.We Present a new method which is taken advantage of primary impedance angle to analyze the WPT system,deduce the model of primary impedance angle,set up the mathematical model of primary impedance angle with the coupling coefficient and secondary quality factor,which could get the effect of frequency splitting and system transfer efficiency with primary impedance angle.Make research of wireless power transfer via coupled magnetic resonances with different construction,a new method of analyze different construction transmission features based on system magnetic field distribution was presented.Make research of relay structure wireless power transfer via coupled magnetic resonances,analyze the change rule of system.The concept of relay coefficient was defined,the best position of relay structure was presented,the reasonable working range was also presented.All of this could present a thinking of system optimization.The method of transmission system performance optimization which based on power transmission analysis was presented.Increase energy capture coil,adjust the output power,this method enhance the system efficiency obviously,this method also could enlarge the transfer distance.Make research for the magnetic field distribution frequency characteristic of wireless power transfer via coupled magnetic resonances,the magnetic field distri-bution frequency characteristic of under-coupling,critical coupling and over-coupling was set.A new method of transmission features influence factor analysis which is based on energy interaction was presented,receiving terminal turn was analyzed,re-ceiving terminal horizontal displacement was analyzed,asymmetric size system was analyzed,this does not has the weakness,which could not consider the structural factor.The method of define wireless power transfer system position information was presented,which could provide guidance for the use and install of system.A pro-grammable control experimental system was projected.We do many related exper-iments,which could verify the theoretical analysis is right.Not only the transporting mechanism,but also the coupling property and struc-tural property of system was researched in a new perspective,frequency analysis method of system was optimized,the analysis method of transfer characteristic fac-tors were improved.Research achievements of this paper enrich the analysis method of wireless power transfer system.All of these lay the theoretical foundation of com-prehensive optimization for transmission distance and efficiency.They also lay the theoretical foundation of improving practicability of wireless power transfer via cou-pled magnetic resonances.