Modeling of a Single-Phase Liquid Cooling System for Power Electronics Applications

Abstract

This work investigates the reliability of a single-phase, liquid cooling system used for the thermal management of a medium power level converter system. The system utilizes a plastic insert cold plate design to provide even cooling over the backside of a power electronics device by directing coolant through parallel serpentine channels. Material selection and compression set testing evaluated suitable elastomers for seals and polymers for the plastic insert. Computational fluid dynamics software was used to evaluate the thermal performance of the cooling system under ideal conditions as well as various wear out conditions (e.g. channel blockage, erosion of channel walls). Properties of used 50/50 ethylene glycol water coolant were evaluated to discover additional causes of reduced thermal performance. After completing the cooling system evaluation under initial and degraded conditions, the impact on a power module's operating temperature was correlated to an estimation of the device's reliability.