Thermal Management and Optimization of Automotive Film Capacitors Based on Parallel Microchannel Cooling Plates

Abstract

The automotive film capacitors (AFCs) stand as a widely employed components in electric vehicles. Yet, a notable concern arises with the potential for excessive ripple current, which can prompt self-heating in the AFC and diminish its reliability. Therefore, it becomes crucial to conduct thermal management and effective heat dissipation design for the AFC to ensure its optimal performance. In this study, considering the trend toward integrated and lightweight motor controllers, a parallel microchannel cooling plate (PMCP) is designed at the bottom of the AFC. Through optimization, the thermal performance of the AFC and the overall cooling performance of the PMCP are enhanced. The AFC thermal model is established, and the calculation method for equivalent thermal properties of the film capacitor core is described. A conjugate heat transfer simulation model for the AFC and the PMCP is created by fluent and validated through two experimental tests. In addition, based on an optimal Latin hypercube sample size, the accuracy of five fitting models is compared and the nondominated sorting genetic algorithm II (NSGA-II) for optimization is employed. The results indicate that the error between the simulation method and the two experiments is within 5%. The application of the PMCP effectively redistributes the hottest region of the AFC to the outer housing, reducing the maximum AFC temperature by 10.90 °C. Among the five fitting models, the response surface model (RSM) proved to be the most accurate. The optimized PMCP enhances the overall cooling performance by 10.32% and increases the maximum withstand ripple current of the AFC by 43.83%.