基于NSGA-Ⅱ算法的无线充电系统磁耦合机构多目标优化

Multi-objective optimization of magnetic coupler for wireless power transfer system based on NSGA-Ⅱ algorithm

针对当前磁耦合机构多目标优化计算量大、计算时间长等问题,本文提出了基于解析表达式和NSGA-Ⅱ算法的多目标优化方法。首先推导了磁耦合机构电气参数和性能参数的解析表达式。在此基础上,以磁耦合机构的尺寸、匝数、匝间距为变量,以传输功率、器件电气应力、绕线可行性为约束条件,以传输效率和功率密度为优化目标,建立了磁耦合机构多目标优化的数学模型。然后,采用NSGA-Ⅱ算法对该数学模型进行求解,得到了一组Pareto最优解集,通过分析各个目标函数的权重,在最优解集中选择一组参数用于设计参考。该设计方法不需要反复的有限元仿真计算,大大减少了计算时间,优化结果证明了该方法的有效性。

To solve the problem of heavy computing burden caused by multi-objective optimization of magnetic coupler in wireless power transfer system,a design method combined by analytical calculation and NSGA-Ⅱ is proposed. First,the analytical expressions of electrical and performance parameters of magnetic coupler are derived. By using physical size,number of turns and coil pitch as variables,transmission power,electronics stress and maximum number of turns as constrains,transfer efficiency and power density as optimization objectives,the mathematic model of magnetic coupler optimization is established. Then,NSGA-Ⅱ algorithm is used to process the multi-objective optimization model and find Pareto optimal solutions. By analyzing the weight of each objective function,a group of parameters is selected for design reference. The design method does not require repeated finite element simulation calculations,which greatly reduces the calculation time. The optimization results prove the validity of the method.