一种永磁同步电主轴转矩脉动和电磁力波的抑制方法

A Suppression Method for Torque Ripple and Electromagnetic Force Wave of Permanent Magnet Synchronous Motor Spindle

针对磁极为平行充磁且两边平行的表面式永磁同步电主轴存在转矩脉动和径向电磁力波的问题,提出一种磁极结构优化方法以抑制转矩脉动和径向电磁力波。基于等效面电流法建立磁极表面半径为任意值的永磁同步电主轴转子气隙磁场的解析模型;综合研究转子气隙磁场对定子开槽电主轴转矩脉动、径向电磁力波的影响;在最小气隙长度不变的前提下,确立优化目标(气隙磁通密度的谐波和幅值),并通过迭代计算的方式得到满足不同优化目标的永磁体磁极结构方案(方案一结构和方案二结构);最后,通过有限元法验证转子气隙磁场解析模型的有效性,并对原结构电主轴、方案一结构电主轴和方案二结构电主轴的转子气隙磁场谐波、转矩脉动、齿槽转矩、平均转矩和径向电磁力波进行对比分析。结果表明:该优化方法可以得到满足不同优化目标的永磁体磁极结构方案,实现原电主轴指定阶次磁通密度谐波、转矩脉动和径向电磁力波的综合抑制。

Aiming at the problem of torque ripple and radial electromagnetic force waves in the permanent magnet synchronous motor spindle whose permanent magnet poles are magnetized in parallel and the two sides are parallel,an optimization method of permanent magnet pole structure was proposed to suppress torque ripple and radial electromagnetic force wave.Based on the equivalent surface current method,an air gap magnetic field analytical model of the permanent magnet synchronous motor spindle with an arbitrary outer surface radius of the magnetic pole was established.The effects of rotor air gap magnetic field on torque ripple and radial electromagnetied force wave of stator slotted motor spindle were comprehensively studied.Under the premise that the minimum air gap length remained unchanged,the optimization objectives(the harmonics and amplitudes of the air gap magnetic flux density)were established,and the permanent magnet structure schemes(scheme 1 and scheme 2)that met different optimization objectives were obtained by iterative calculation.Finally,the validity of the analytical model of the rotor air gap magnetic field was verified by the finite element method.The rotor air gap magnetic flux density harmonics,torque ripple,cogging torque,average torque and radial electromagnetic force wave of the original structure motor spindle,the scheme 1 structure motor spindle and the scheme 2 structure motor spindle were compared and analyzed.The results show that the optimization method can be used to obtain permanent magnet magnetic pole structure schemes that meet different optimization objectives,and the comprehensive suppression of specified order magnetic flux density harmonics,torque ripple and radial electromagnetic force wave of the original motor spindle is realized.