基于目标参数最优的磁耦合谐振式无线能量传输系统频率特性分析及仿真验证

Analysis and Simulation of Frequency Characteristic Based on Optimal Objective Parameter in Magnetically-Coupled Resonant Wireless Power Transfer System

磁耦合谐振式无线能量传输技术能实现中等距离的高效能量输出,表现出极大的应用潜力.在该技术中,频率的变化会对系统传输性能产生重要的影响.因此频率特性分析对提高系统性能具有重要的意义.在考虑线圈内阻的条件下,利用阻抗反射理论分析了4种拓扑结构下距离和负载的变化对系统发射端谐振补偿策略的影响,发现串串型拓扑结构的频率稳定性最好.基于互感理论分析了在理想和非理想状态下距离和负载的变化对系统最佳工作频率的影响.在MATLAB环境下建模分析验证了上述理论的正确性.利用插值法和多项式拟合对理想状态下传输效率的最佳工作频率进行仿真分析.结果表明,样条插值和8次多项式拟合效果最好,可为后期提高频率控制的精确性提供一定的参考.

Magnetically coupled resonant wireless power transfer(MCR-WPT)has the advantages such as mid-range and high efficiency and shows great application potential.In this technology,the change of frequency has an important impact on the transmission performance of the system.Therefore,the analysis of frequency characteristics is of great significance to improve the performance of the system.The increase of resonant topological strategy is sending terminal,resulting from the variation of loads and transmission distance,is analyzed theoretically through the reflect impedance theory taking coil resistance into account in four topological structures.It is found that series-series topological structure has the most stable frequency property.Besides,this paper researches the relationship between optimal operating frequency and variations of loads,transmission distance in the desiable and undesiable cases by means of multual inductance theory.Modeling and analysis in MATLAB environment verify the correctness of the above theory.The interpolation method and the polynomial fitting are used to simulate and analyze the optimal operating frequency of transmission efficiency under ideal state.The results show that spline interpolation and 8 th order polynomial fitting are the best,which can provide some references for improving the accuracy of frequency control in the later period.