Thermal Modeling And Measurement Of A Traction Motor In A Production Pure Electric Vehicle

This paper presents the thermal modeling and measurement of an electric traction motor used in a production electric vehicle, i.e., GAC's 2017 pure electric SUV GE3. The motor is a high-efficiency permanent magnet (PM) synchronous motor which is actively cooled by circulating coolant through a water jacket. The motor's electromagnetic loss (i.e., internal heat generation) in the stator and rotor was modeled and measured at typical conditions, which was used as input to the thermal simulations. To achieve accurate modeling results, the axial thermal conductivity of the motor's stator/rotor lamination stack was measured to be similar to 3.5 W/m-K using special equipment. Theoretic heat transfer analysis, CFD numerical simulation, and lumped parameter thermal network (LPTN) method were conducted to model the heat transfer of the traction motor. Measurement of the rotor temperature using slip ring and infrared (IR) thermography validifies the CFD and lumped parameter thermal network (LPTN) modeling results.