On the Edge of Passive Cooling for Power Converters: Review and Future Trends

High-power-density converters and inverters play a vital role in modern technologies, from electric vehicles (EVs) to power infrastructure like superchargers and transformers. As designers strive for greater efficiency and lower costs, managing the heat generated by these compact, high-performance systems has become a key challenge-especially since power devices are the main contributors to thermal buildup. Excessive heat can compromise reliability and limit further size reduction, making thermal management a critical aspect of system design. While active cooling solutions are effective, passive cooling technologies—such as heat sinks, heat pipes, and thermal interface materials (TIMs)—offer compelling benefits, including smaller footprint, simpler implementation, and lower cost. However, evaluating their feasibility and performance for specific use cases remains a complex task. This review examines a range of passive cooling methods, compares their strengths and limitations, and proposes a structured methodology for assessing their applicability in various high-power-density scenarios.