Jet Impingement Cooling of Power Modules for Automotive Power Electronic Applications: Design, Fabrication, and Analysis

Abstract

Several cooling types are currently deployed in electric vehicles to reduce the temperature related failures of power electronic modules, including liquid coldplates and air-cooled heatsinks. Typically, these cooling systems use a horizontal flow path, which flows parallel to the heat-generating components. However, by moving the flow path from a horizontal orientation to a vertical one, an increase in heat transfer can be realized due to the increase in turbulence. The most common of these vertical cooling solutions is jet impingement. While jet impingement has been studied for decades and used as a cooling method in several applications, it has yet to be implemented as a commercial power electronic cooling method for electric vehicles. However, as the power density of power electronics increases, designs reduce pressure losses, and new manufacturing methods evolve, jet impingement is the next step in power electronic cooling. As electrical characteristics depend on the device temperature, analyzing the modules with electro-thermal coupled simulations is common. However, despite the abun- dance of transient models in the literature, drive cycle studies have yet to be done with jet impingement cooling. By accounting for these changing heat loads, a more comprehensive analysis of the power module performance can be realized. Therefore, this thesis will discuss the numerical modelling of jet impingement at the maximum power losses for the power module and compare it to a baseline cooling system. A transient drive cycle model is also created to analyze the thermal performance of the baseline and jet impingement cooling. Furthermore, validation through experimental testing finds the modelling accurate within 11%, and the jet design decreases the maximum temperature by 16 ◦C.