Overview of Current Thermal Management of Automotive Power Electronics for Traction Purposes and Future Directions

The design of the thermal management solution has a significant impact on the reliability and power density of power electronics (PEs). As the electric vehicle (EV) industry moves toward increasing the efficiency and output power, the cooling system must effectively remove the excess heat dissipated in PEs. The main heat-generating components are the semiconductor switches, but other components, such as bus bars and power capacitors, also dissipate heat and require cooling. Currently, indirect, direct, and double-sided cooling methods are the most common in EVs and account for 14%-33% of the total volume of traction inverters. However, PE packaging sizes are expected to decrease, while the heat dissipation continues to increase; hence, advanced cooling technologies are being investigated. This article aims to review the thermal management strategies for major PE components in EVs as well as their failure modes since high temperatures can be detrimental to the performance of PEs. Cooling designs that are currently implemented in EVs and future cooling trends for the next generation of PEs are reviewed as well.