摘  要：该文用解析数值结合法分析直驱式外转子分数槽表面磁钢永磁无刷电机气隙磁场。将磁场求解范围划分为等效气隙区域和扩展槽区域，根据等效气隙区域磁位解析解得到开槽后扩展槽区域数值计算的第一类边界条件，永磁体等效成面电流密度，用四边形等参元法计算扩展槽区域磁场分布。电机转子转动，可计算任意气隙半径处磁密分布和任意角度的齿槽定位转矩。通过对计算结果的分析验证此方法在外转子表贴式电机气隙磁场计算中的正确性。
关键词：直驱式;分数槽;表面磁钢式；永磁无刷电机;气隙磁场;解析数值结合法

Abstract: Air-gap magnetic field of the direct-drive outer rotor surface-mount permanent magnet fractional slot brushless motor was analyzed in the analytical-numerical method. The domain of the magnetic field was divided into the equivalent air-gap area and the extend slot area. The first boundary condition of the extend slot areas in the condition of stator slotting was acquired according to the magnetic vector potential analytical solutions of the equivalent air-gap areas. The permanent magnets were equivalent to surface current density. The uadrilateral isoparametric element method was used to calculate the magnet field of the extend slot area. Both the distribution of air-gap flux density at any radius location and the value of cogging torque at any angle position can be computed, when the motor rotated. The result verified the validity of the method calculating the air-gap magnetic field of outer rotor surface-mount permanent magnet motor.
Key Words: Direct-drive, Fractional slot, Surface-mount permanent magnet; Brushless motor, Air-gap magnetic field, Analytical-numerical method