双边空心式永磁直线伺服电机的横向边缘效应

针对双边空心式永磁直线伺服电机横向边缘效应较大,会影响气隙磁场分布、使空载反电势和推力幅值减小的问题,研究量化横向边缘效应影响的方法.定义横向漏磁系数,通过将该电机三维有限元和二维有限元气隙磁场的分析结果进行对比,推导出横向漏磁系数的计算公式.该系数主要受电机横向长度、气隙高度和永磁体厚度的影响,可对二维有限元结果进行修正.实测结果表明,修正后的二维有限元结果更加接近实测值,证明了该方法的正确性和有效性.

Transverse end-effect analysis of double side air-cored permanent magnet linear servo motor

The double side air-cored permanent magnet linear servo motor (PMLSM) has larger transverse end effect which will affect the air-gap magnetic field, no-load back electromotive force (EMF) and thrust. A flux leakage coefficient was defined to quantify the end-effect, and the calculation method of the coefficient was obtained through the comparison of the flux density predicted from two dimensional and three dimensional finite element analysis. The coefficient was mainly affected by motor’s transverse length, air gap length and magnet thickness, and can be used to modify the two dimensional predicted results. The revised results accorded well with the actual values, which proved the correctness and validity of the method.