Study on Heat Exchange of Different Ventilation Structures of Asynchronous Traction Motor for High Speed EMU

Background: Aiming at the problems of high local temperature and uneven temperature distribution in asynchronous traction motor of high-speed Electric Multiple Unit (EMU) when it is running. Aim: In this paper, the influence of ventilation system with different structure on temperature distribution is studied. Methods: Taking 600kW asynchronous traction motor as an example, the electromagnetic-fluid-temperature analysis model of the traction motor is established, and the temperature values of different positions in the motor are obtained. The accuracy of the calculation results is verified by comparing with the actual measurement. On this basis, by adjusting the structure of stator and rotor axial ventilation holes, the relationship between temperature distribution and fluid flow state in motor is studied. In addition, the influence of fluid incidence angle on fluid velocity and heat dissipation performance of motor is also studied, and the ventilation structure scheme with relative balance of axial and circumferential temperature in motor is found out, which provides a reference strategy for the design of temperature rise of motor with forced ventilation structure. Results: The wind speed near the intake side of stator teeth and rotor teeth groove is less than that far from the intake side. The flow distribution trend of rotor vent is similar to that of stator vent, but the air in the groove is affected by centrifugal force of rotor rotation, which makes the wind speed difference on the intake side larger than that on the outlet side. The stator winding and rotor guide bar are affected by wind temperature to reach the maximum temperature at the end of the outlet respectively. The stator core is higher at the windward side and the leeward side than the other parts of the motor. The heat dissipation effect at both ends is good. The highest temperature of the stator core appears near the leeward side.