基于遗传算法的飞轮储能系统用径向永磁轴承的优化设计

Optimization design of the radial permanent magnet bearings of the flywheel energy storage systems based on genetic algorthm

对飞轮储能系统用径向永磁轴承设计中径向永磁轴承承载力和结构参数优化的问题进行了研究。在永磁体空间磁场分布解析式的基础上,结合根据分子电流学说建立的环形电流模型,推导出径向永磁轴承的径向力解析表达式;定义径向力密度衡量轴承性能优劣;根据优化理论建立以径向力密度为目标函数的优化模型;最后考虑到单因素变量法的缺陷,采用遗传算法理论和方法,利用MATLAB编程求解轴承结构参数的最优结果。对结果分析可知,轴承最佳的结构参数并不是单因素变量法分析的轴承横截面为正方形。总结了永磁轴承设计的一般步骤和方法,对飞轮储能系统径向永磁轴承的设计有实际的指导意义。

In order to solve the design problem of radial magnetic bearing that used in flywheel energy storage system,the problem of the radial permanent magnet bearing capacity and the structure parameter optimization is studied.According to the molecular current theory,the permanent magnet ring current model is established.Combined with the analytic expression of the distribution of permanent magnetic field that deduced on the basis of equivalent current,then the radial force analytic expressions of the radial permanent magnet bearings is deduced.And define the radial force density as a measure of the bearing performance.In consideration of the defects of single factor variable method,and in accordance with optimization theory,the theory and method of the genetic algorithm,the optimization model is established.The optimal results of the bearing structural parameters are obtained by using MATLAB software.And the analysis results shows that the bearing structural parameters are not as same as the results that bearing cross section are square by using single factor variable method.Finally the general methods and steps of permanent magnetic bearing design,which is used in the flywheel energy storage system,are summarized.These have practical guiding significance to the design of radial permanent magnet bearings which is used in the flywheel energy storage system.