永磁同步电机电磁振动数值预测与分析

Numerical Prediction and Analysis of Electromagnetic Vibration in Permanent Magnet Synchronous Motor

建立了考虑电磁力空间分布和定子等效的永磁同步电机电磁振动仿真计算模型。首先通过麦克斯韦应力张量法推导了电磁力的空间和频率特征,并考虑常见的电流谐波对电磁力频率特征的影响,之后通过有限元方法计算定子齿表面的电磁力。其次建立了考虑铁心和绕组材料各向异性的定子结构有限元模型,通过模态试验进行验证。最后将电磁力从电磁网格转移到结构网格上通过模态叠加法计算电磁振动,仿真计算结果与试验结果吻合较好,并对比了分布力与集中力两种力加载方法下的电磁振动结果。通过该文的研究发现考虑电磁力的空间分布和定子等效是电磁振动准确预测的关键因素,同时仿真与试验结果均表明开关频率附近的电流谐波对电磁振动影响显著。

A prediction model for electromagnetic vibration calculation of permanent magnet synchronous motor （ PMSM） accounting for effects of electromagnetic force spatial distribution and stator equivalence is established in this paper. Firstly, Maxwell stress tensor method is used to analyze the spatial and frequency characteristics of electromagnetic force. The effects of current harmonics on the frequency of electromagnetic force are also taken into account. By using finite element method （ FEM ） , the force acting on the surface of stator teeth is calculated firstly. Then the stator structural model accounting for material anisotropic of stator core and winding is built and modal test is conducted to validate this model. Finally, the mode superposition method is used to calculate the electromagnetic vibration when electromagnetic force is transferred from electromagnetic model to structural model. The calculated results agree well with those by test. Besides, the characteristics of distributed force and equivalent concentrated force are compared. It is shown in the research of this paper that the effects of electromagnetic force spatial distribution and stator equivalence are key factors for vibration calculation. The current harmonics close to the switching frequency significantly influence the vibration according to the simulation and test results.