Research On Coil Parameters Optimization And Double-Side Tuning Control Of LCC/S-WPT System

At present,Wireless Power Transfer(WPT),a new form of power transmission without direct electrical contact,has been selected as one of the ten future research directions by the American "Technology Review" magazine.Compared with traditional transmission methods,WPT has higher security and is more convenient and flexible in application.However,due to the high spatial freedom of the coupling mechanism,the uncertainty of its relative position will lead to the fluctuation of the coupling parameters,resulting in the degradation of the coupling coefficient and frequency detuning phenomenon,thus reducing the transmission efficiency of the system and affecting the stable output of the system.Therefore,it is of great significance to carry out the research on the optimal design of the coupling mechanism and the frequency tuning control under the misalignment condition of WPT system.For the optimal design of coupling mechanism parameters under misalignment conditions,most of the traditional methods rely on the exhaustive attack method and finite element analysis(FEA)to achieve,which has the disadvantages of complex modeling and time-consuming.To overcome these limitations,this paper proposes a genetic algorithm(GA)-based optimization strategy for the coil parameters of the hexagonal coil LCC/SWPT system,taking into account the transmission efficiency and the actual power requirements.Firstly,a direct integration method is proposed to simplify the analytical solution process of the mutual inductance between hexagonal coils.Based on the improved mutual inductance model,through the control variable method,the transmission characteristics of the coil are deeply analyzed,and the optimization objective function and constraints are proposed based on the transmission loss of the coil under the offset condition and the actual efficiency requirements of the system.Finally,the multiparameter optimization of the hexagonal coil is automatically realized by GA.For frequency detuning of WPT systems due to parameter drift,the traditional singleside tuning control cannot achieve complete compensation of the system,and the doubleside tuning control using wireless communication has a coupling problem.To this end,this paper focuses on proposing a bilateral decoupled tuning control strategy for LCC/SWPT systems,which can realize double-side decoupled tuning of the system without communication and parameter identification.Firstly,the relative electrical characteristics when the primary and secondary sides of the system reach the resonance state are emphatically analyzed.On this basis,the zero phase angle(ZPA)control method based on optimal efficiency tracking and the double-step perturbation and observation method with maximum current search are proposed to adjust the parameters of the primary and secondary side compensation network adaptively,and realize double-side tuning decoupling control.In this paper,an efficiency optimization strategy is proposed for the LCC/S-WPT system from the aspects of the parameter optimization of the coupling mechanism and the frequency tuning control.The correctness of the proposed control algorithm is verified by in-loop simulation based on the PSIM simulation software and the DSP28335 development board.Finally,the experimental platform of the 200 W WPT system was built,and the effectiveness of the double-side adaptive tuning LCC/S-WPT system is verified by simulation and experiment,and the maximum transmission efficiency of the designed system reaches 93.7%.