中文摘要：

针对永磁直线电机的推力波动问题，首先针对整数槽绕组多段式初级铁芯结构圆筒型永磁直线电机，提出了采用初级铁芯依次沿纵向移距的方法削弱电机的齿槽力，并基于能量法推导了初级铁芯模块移距法削弱齿槽力的机理，给出了初级铁芯模块移距的计算公式；其次，针对初级铁芯模块移距引起各段相电动势的分布的情况，给出了空载电动势等效分布系数的计算公式；最后，进行了有限元分析及试验。结果表明：初级铁芯模块移距后，电机的齿槽力得到了有限的抑制，大大降低了空载电动势中的谐波含量，相空载电动势波形更加正弦化。

英文摘要：

A method of restraining the cogging force in tubular permanent magnet linear motors with multi-segment primary based on primary iron-cores shifting is proposed. The mechanism of weakening cogging force in tubular permanent magnet linear motors with primary iron-cores shifting is analyzed based on the energy method. A formula of arranging the primary iron-cores is presented. The studies show that the back-EMF of each primary iron-core is distributed with primary iron-cores shifting, and the equivalent winding distribution factor of tubular permanent-magnet linear synchronous motors with multi-segment primary is deduced. Finite element analysis and experimental results show that cogging force and harmonic back-EMF are effectively suppressed and no-load EMF waveform is more likely to be sinusoidal.