中文摘要：

为实现应用于步进扫描投影光刻机中长行程直线电机的高推力密度、低推力波动等要求，研究叠放和非叠放两种分数槽集中绕组的无铁心永磁直线同步电机推力特性，在建立空载气隙磁场分析模型的基础上，推导叠放和非叠放两种绕组形式的电机空载感应电动势、电磁推力和推力密度的解析式，分析永磁体和初级绕组的结构尺寸对电磁推力的影响规律。通过实例分析。比较推力的解析法计算结果、有限元法仿真结果和实验测试值，证明解析法的合理性。同时，分析比较不同极槽比组合的叠放和非叠放分数槽集中绕组的电机电磁推力和推力密度的大小。结果表明：少极多槽极槽比的叠放分数槽集中绕组形式电机产生的电磁推力与推力密度更大。

英文摘要：

In order to achieve high thrust density and low thrust ripple of long stroke linear motors ap- plied to step and scan projection lithography, thrust characteristic of air-core permanent magnet linear synchronous motors with overlapping and non-overlapping fractional slot concentrated windings were researched. Based on the no-load magnetic field analysis model, analytical formulae of no-load in- duced electromotive force, electromagnetic thrust and thrust density of motors with overlapping and non-overlapping two windings styles were deduced, and influence rule of variations of electromagnetic thrust with structure and sizes of permanent magnets and the primary windings was analyzed. Through the example analysis, compare the results of analytic method, finite element analysis method and ex- perimental test, prove the rationality of the analytic method. Meanwhile, the values of electromagnetic thrust and thrust density of motors with overlapping and non-overlapping fractional slot concentrated windings for different pole/slot ratio combination was analyzed and compared. The results show that the motor with overlapping fractional slot concentrated windings of more poles and less slots pole/slot ratio produces greater electromagnetic thrust and thrust density.