Design of a Compact Thermal Management System for a High-Power Silicon Carbide Traction Inverter 2021-01-0218

This paper presents a compact thermal management solution for a high-power traction inverter. The proposed design utilizes a stacked cooling system that enables heat extraction from two of the largest heat sources in a power inverter: the power module and the DC-link capacitor. The base plate of the power module has circular pin fins while the capacitor comes with a flat surface which must be placed on a cold plate to provide the adequate heat dissipation. Incorporating individual cooling mechanisms for the DC-link capacitor and the power module would increase the weight, complexity and overall volume of the inverter housing. The proposed cooling system mitigates these problems by integrating the cooling mechanisms of the power module and the DC-link capacitor within a single cooling system. The cooling mechanism is designed to provide a uniform coolant flow with minimal pressure drop across the heat sink of the power module and DC-link capacitor. The uniform coolant flow also ensures minimal coolant temperature gradient across the switching devices in the power module and the capacitors cells. This maintains a uniform junction temperature in the capacitor cells and the switching devices. The proposed design is validated using Computational Fluid Dynamics.