中文摘要：

通过解析法和有限元法对双边空心式永磁直线伺服电机的磁场和推力特性进行了分析.采用等效磁化强度法,将永磁体等效为磁化强度分布函数,建立磁场向量磁位的微分方程组并采用分离变量法进行求解,推导出磁通密度的解析公式.同时采用AnsoftMaxwell软件对电机磁场进行了有限元分析,结果证明磁通密度解析公式是准确的.针对5极/3线圈短距绕组结构的电机,推导出电机动态推力的解析公式,解析法推力计算结果与有限元法计算结果的相对误差为3.28%,证明推力解析公式是准确的.推力解析公式表明,当电机电枢电流为正弦电流时,电机推力仅含有6倍频的谐波分量,且推力波动小.气隙磁场和推力解析公式有助于分析电机磁场分布和推力波动情况,为电机优化设计提供基础.

英文摘要：

The magnetic field and thrust of the double side air-cored permanent magnet linear servo motor （PMLSM） were analyzed by analytical method and finite element method （FEM）. The permanent magnets （PMs） were equivalent to the magnetization intensity distribution function based on the analytical method of equivalent magnetization intensity. The differential equations of the magnetic potential vectors were built up and solved by the separation variable method,and the analytical formulas of the magnetic flux density were derived. The magnetic field of the motor was also analyzed by FEM using the Ansoft Maxwell software,and the solutions of the FEM verified the correctness of the magnetic flux density formulas. Based on the 5-poles,3-coils short pitch winding structure,the dynamic thrust formula of the motor were derived. The relative error of the thrust computed by formula and FEM was 3.28%,which proved the accuracy of the analytical solution. The thrust formula shows that only six-octave harmonic thrusts exist while the armature currents are perfect sinusoids,and the ripple thrust is very small. The analytical formulas are helpful for analyzing the magnetic field and thrust ripple which provide the basement for the motor optimization.