| With the increase of the demand of wireless power transmission technology,power transmission is no longer restricted by site,maintenance,reliability and other factors.And it has received extensive attention.However,in practical application,the relative displacement between the primary and secondary sides of the loosely-coupled transformer is inevitable,which often leads to great fluctuations in the output voltage or current,and reduces the transmission efficiency of the system.Therefore,the antimigration performance of the system must be enhanced.In view of the above problems,this paper optimizes the loose-coupled voltage transformer and compensation network to reduce the fluctuation of the coupling coefficient during the loose-coupled transformer migration,and at the same time enhances the stability of the output voltage or current of the system.In this paper,a new type of D.D.D.is proposed based on the theoretical analysis of the traditional loosely-coupled transformer structure.The coupling system variation trend of the system during migration is analyzed from the perspective of magnetic field lines and magnetic field atlas,and it is proved that the structure has strong anti-migration ability.By analyzing the magnetic field distribution in the horizontal and vertical directions of the D.D.D.type loose coupling transformer,it is proved that the proposed structure can achieve the anti-offset ability improvement and magnetic shielding characteristics at the same time.Finally,the optimization parameter design method of the proposed D.D.D.type loose coupling transformer is proposed,which proves that it can adapt to different actual requirements by changing the coil turns ratio.Because there is flux leakage in the radio energy transmission system,it is impossible to analyze it by using the traditional transformer model.In this paper,the classical T-type equivalent model and mutual inductance equivalent model are analyzed and the two-port network equation of symmetrical structure is deduced.A symmetric PS/SP topology based on frequency modulation control is proposed.By analyzing the influence of output voltage equiratio conditions and system input zero phase Angle conditions on the output characteristics of the system,It is proved that the system has a special frequency under the condition that the input and output voltages are equal and the input phase Angle is zero,and it is verified by simulation.In this paper,the stress analysis of each element under the condition of zero phase Angle solution is carried out,and an optimized parameter design method is proposed.In this paper,AD8302 and related accessories are used for phase Angle acquisition,and a closed-loop control system based on AD8302 with high precision is designed.Then,by analyzing the influence of load,self-induction and short-circuit interval on the sweep curve of the system,the method of selecting and adjusting the topology optimization parameters was proposed.Finally,the system with selected topological parameters is simulated with different coupling coefficients,which verifies the zero-phase Angle solution theory mentioned above,and also proves that the structure has strong anti-migration abilityFinally,based on the above analysis,a prototype with an output power of 250 W is built with an efficiency of 88%,which verifies that the proposed loosely-coupled transformer and compensation network have strong anti-migration ability. |
