Research On Compensation In Inductively Power Transmission Based On Axial Loosely Coupled Transformer

Inductively coupled power transmission technology is widely used in electric vehicles,mines,aerospace,underwater detection because of its frictionless,non-electrical spark and wireless transmission under relative motion.The loosely coupled transformer and its compensation structure are the core parts of the wireless transmission system,which will directly affect the performance of the entire wireless power transmission system.In this paper,the magnetic circuit analysis of a typical loosely coupled transformer is introduced.The simulation model of the axial loosely coupled transformer based on COMSOL is built.The calculation method of the transformer parameters is introduced.The simulation analysis of flux distribution and parameter changes are made when the relative positions of the primary and secondary sides are changed.Secondly,In view of the low transmission power of inductively power transmission technology,this paper studies the compensation of the loosely coupled transformers.In this paper,the parameter setting method of LCC structure in sinusoidal and square voltage source is studied.LCC/S and LCC/P compensation methods based on LCC structure combined with single-order compensation are proposed,the transmission characteristics of two compensation methods are studied.The transmission power is also studied when the relative positions of the primary and secondary sides of the transformer are changed.The harmonic characteristics of LCC,LCC/S and LCC/P compensation are analyzed.Thirdly,the core and coils loss of the axial loosely coupled transformer and the loss of compensation device are analyzed.The equivalent series resistance is used to characterize the loss of the compensation capacitor and the inductance.The loss circuit model of ICPT system based on mutual inductance model is established.The transmission efficiency characteristics of LCC/S and LCC/P compensation are studied,and the conclusion that LCC/S compensation is better than LCC/P compensation is obtained.The frequency selection method of ICPT system is proposed based on the transmission characteristics of LCC/S compensation,and the loss characteristics,transmission characteristics and output stability under the optimal frequency are simulated.Finally,the parameters of the axial loosely coupled transformer are obtained through experiments,and the ICPT system experiment platform with compensation structure is built.The characteristics of soft-switching,constant-voltage and large-capacity transmission of LCC/S compensation are verified.