为研究全封闭大功率永磁牵引电机额定工况下的稳态温度场，以一台额定功率为815 kW的永磁同步牵引电机为研究对象，依据成型绕组槽部导热模型，建立了整机三维温度场共轭传热计算模型。考虑旋转磁化、冲压过程和磁密高阶谐波对定子铁耗的影响，以及水套-定子铁心间接触热阻抗对电机温升的影响，采用Fluent软件对电机额定工况下的稳态流场与温度场求解，使用电阻法和埋置检温计法（ETD）测得电机在额定工况下绕组的平均温升、铁心测点和绕组端部测点局部温升，绝对误差分别为-3.7 K、-0.3 K和7.6 K。进一步分析了电机水路和内风路流场分布特性、水套-定子铁心间接触间隙对绕组平均温升的影响以及槽内绕组附近的温升分布情况，最后提出了该类电机冷却系统设计优化方向。

In order to study the steady-state temperature field of a fully enclosed high-power permanent magnet traction motor under rated condition, a three-dimensional conjugate heat transfer model of temperature field of a permanent magnet synchronous traction motor with rated power of 815 kW is established based on the heat conduction model of the formed winding in slot. Considering the influences of rotating magnetization, stamping process and high-order harmonics of flux density on stator iron loss, and the influence of contact thermal impedance between water jacket and stator core on motor temperature rise, the Fluent software is used to solve the steady-state flow field and temperature field of the motor under rated condition. The average temperature rise of the winding and the local temperature rises at the measuring points at the stator core and the end of the winding are measured by the resistance method and the embedded temperature detector (ETD) method under the rated condition, and the absolute errors are -3.7 K, -0.3 K and 7.6 K, respectively. Furthermore, the flow field distribution characteristics of water and internal air path of the motor, the influence of the contact gap between water jacket and stator core on the average temperature rise of the winding, and the temperature rise distribution near the winding in the slot are analyzed. Finally, the design optimization direction of the motor cooling system is proposed.