Impact of Immersion Cooling on NPC Multilevel Converters

This technical report investigates the impact of immersion cooling on the thermal distribution of semiconductor switches in Neutral Point Clamped (NPC) multilevel converters, particularly for applications in electric aircraft propulsion systems. The report outlines the challenges associated with unbalanced loss distribution among semiconductor switches, which limits the performance of NPC converters. It presents a novel immersion cooling technology designed to enhance thermal management by providing uniform cooling and improved dielectric insulation. The study compares the performance of immersion cooling against conventional heatsink cooling methods, demonstrating that immersion cooling significantly reduces hotspot temperatures and achieves a more uniform temperature distribution within the inverter. The report also discusses the advantages of immersion cooling, including its compact design, cost-effectiveness, and reliability in high-altitude aviation applications. The findings suggest that immersion cooling may be a viable solution for improving the efficiency and reliability of power converters in electric propulsion systems.