中文摘要：

针对异步起动永磁同步电机气隙磁场谐波复杂，而导致的铁心损耗大、电磁噪声高、转矩脉动强烈等不利问题，提出了电机气隙长度不均匀的方法，用以减小气隙磁场谐波，进而减小电机铁心损耗、降低电机电磁噪声、抑制转矩脉动，计算并校验了电机永磁体的最大去磁工作点。有限元仿真表明，所提出的不均匀结构电机的气隙磁场谐波大幅下降，电机转矩脉动得到有效地抑制；电机在额定转矩、三倍转子转动惯量负载的情况下，满足异步起动能力；起动过程中永磁体在最强退磁点的剩磁也符合设计要求。

英文摘要：

As for the problems of heavier core loss, higher unfavorable electromagnetic noise, and more complex air gap field harmonics of line-start permanent magnet synchronous motor （ LSPMSM ）, a LSPMSM prototype with uneven air gap was proposed to reduce gap magnetic field harmonics, thus to decrease motor core loss and electromagnetic noise. Maximum operating demagnetization point of permanent magnet was cal- culated and verified. Results of FEM analysis of asynchronous motor with uneven air gap indicated that proto- type motor structure could achieve an asynchronous start at the conditions of rated torque and three times the rotor inertia. At rated load operation, air gap field harmonics dropped significantly, permanent magnet rema- nence also fulfils design requirements at the strongest demagnetization point.