Temperature fields analysis and heat dissipation structure design of an film capacitor in new energy vehicle

The high temperature resistance performance of film capacitors in motor controllers faces greater challenges with the development of high voltage and high power density of new energy vehicles. In this study, a typical film capacitor is taken as the object of research, simulations of temperature fields, and experiments on temperature rises are conducted. Additionally, a heat dissipation structure is designed to enhance the high temperature resistance performance of the capacitor. Firstly, the temperature field distributions of the capacitor under different ripple currents and ambient temperatures are analyzed using ANSYS electro-thermal coupling simulation. Then, under the same operating conditions, experiments on the temperature rises are conducted on the capacitor, which is installed with K-type thermocouples to verify the accuracy of the electro-thermal coupling simulation. Furthermore, an external heat dissipation structure consisting of a micro-channel liquid cold plate is designed for the capacitor, and the effectiveness of the external cold plate is verified through electro-thermal coupling and FLUENT simulations. It is found that under the operating conditions of 85?C ambient temperature and 175 A ripple current, the maximum temperature of the capacitor with the external cold plates decreases by 46.08% compared to the original capacitor. The results indicate that the external cold plates effectively improve the high-temperature resistance capability of the film capacitors in electric vehicles.