考虑端部效应的永磁直线电机等效磁路模型

Magnetic Equivalent Circuit Model for Permanent Magnet Linear Motor Considering End Effect

为了提高永磁直线电机的仿真速度,提出了一种考虑端部效应的改进等效磁路模型。首先,不包括直线电机端部齿,交链每个初级齿的磁场被划分为4个磁路支路,分析了支路参数的周期性;其次,通过比较磁力线的长度,将永磁极之间的漏磁通与主磁路分离,建立了单独的漏磁磁路;最后,通过分析有限元方法获得的端部磁场,构造了2条附加支路,建立了直线电机的等效磁路模型,并进行了简化。等效模型考虑了齿槽效应、磁饱和和电枢反应,并在电机运行时保持拓扑结构不变,只需改变支路参数。以8极9槽永磁直线电机为例,通过与二维有限元仿真结果进行比较,验证了所提模型的有效性。

To improve the simulation speed of permanent magnet linear motor （PMLM）, an improved magnetic equivalent circuit （MEC） model is proposed considering end effect. Firstly, the magnetic field of each primary tooth except the end teeth are divided into four magnetic branches, and the periodicity of branch parameters is analyzed. Secondly, through the comparison of the lengths of flux lines, the leakage flux between permanent magnetic poles is separated from the main flux, thus an individual leakage circuit is built. Finally, by analyzing the fringing magnetic field obtained by finite element analysis （FEA）, two additional branches are constructed. In this way, the MEC model of PMLM is built and simplified. The equivalent model considers slot effect, magnetic saturation and armature reaction. Further- more, its topological structure can be kept fixed during the operation of PMLM, and merely the branch parameters need to be changed. Taking an 8-pole 9-slot PMLM as an example, the validity of the proposed model is verified from the comparison with the results of 2D FEA.