电机定子铁芯振动特性分析的一种解析方法

随着新能源汽车的发展,用户对电机噪声的要求日趋严格,噪声振动分析已经成为电机开发中的重要内容。定子的电磁振动是电机的主要噪声源,由于电机定子的复杂结构,目前常用有限元方法建模分析定子铁芯的振动特性,耗时太长,不能满足定子优化设计的振动噪声特性快速计算要求。提出了一种解析方法用于计算定子铁芯的振动特性。采用厚壳-梁耦合结构对定子铁芯进行简化,计入了定子齿对振动特性的影响;推导了耦合结构的解析能量泛函,并使用Rayleigh-Ritz法计算出定子铁芯的固有频率和模态振型。应用该解析方法计算了电机定子振动特性,分析了定子齿枢的影响,并与商用软件的有限元建模分析结果进行比较,两者误差小于5%,验证了该解析方法的准确性。

An analytical method for vibration characteristics analysis of motor stator core

With development of new energy source vehicles,motor noise requirements of users are increasingly strict,noise and vibration analyses become an important part of motor development.Electromagnetic vibration of stator is the main noise source of a motor.Due to the complex structure of stator,the finite element(FE)method is usually used to model and analyze vibration characteristics of stator core,and it takes too long time to meet rapid calculation requirements of vibration and noise characteristics of stator optimization design.Here,an analytical method was proposed to calculate vibration characteristics of stator core.A thick shell-beam coupled structure was adopted to simplify stator core,and effects of stator teeth on vibration characteristics were considered.The coupled structure’s energy functional was derived using interface continuity conditions.Rayleigh-Ritz method was used to calculate a stator core’s natural frequencies and modal shapes.Finally,the proposed method was applied to calculate vibration characteristics of a certain stator core,and effects of stator teeth were analyzed.The results obtained with the proposed analytical method were compared with those obtained with the famous FE software.It was shown that the error between them is less than 5%to verify the correctness of the proposed analytical method.