Temperature Rise Characteristics Research of Integrated Electric Drive System for Vehicles

Calculating the temperature rise of a component of the electric drive system (EDS) alone is no longer sufficient to meet the design requirements, so it is necessary to calculate the temperature of the whole integrated EDS to obtain the temperature rise characteristics of the EDS. The temperature field of a three-in-one integrated EDS is simulated at four operating conditions using the fluid–solid coupled finite element method. The four operating conditions are rated power and rated speed, rated power and peak speed, peak power and rated speed, and peak power and peak speed. The losses of components of the EDS at the four operating conditions are calculated, and the heat transfer coefficients of the components of the EDS are also obtained. Then the temperature of the EDS is calculated and compared with the experiment, after that the temperature rise characteristics of the EDS are researched. The results show that the simulated temperature of the motor winding at rated power and rated speed is 3 °C higher than the experimental value with an error of 2.54%, and the simulated temperature of the motor winding at rated power and peak speed is 3 °C higher than the experimental value with an error of 2.58%. The temperatures of other components of the EDS are also within the limits. When the power is the same, compared with the rated speed condition, the temperature rises of the stator core, rotor core and reducer components are higher and the temperature rises of the winding and IGBT module are lower at the peak speed condition.