Comparison of the Heat Transfer Capabilities of Conventional Single- and Two-Phase Cooling Systems for an Electric Vehicle IGBT Power Module

This paper presents a comparison of conventional single-phase water/glycol liquid and innovative two-phase cooling technology for thermal management of high-power electronics automotive insulated-gate bipolar transistor modules during a full drive cycle. The proposed two-phase cooling system is built using conventional automotive air conditioning components (a condenser, an expansion valve, a compressor, and vapor and liquid lines) and a conventional cold plate as used for single-phase cooling; thus, the design does not require the development of new technology for its implementation. Three-dimensional numerical simulation in COMSOL and experimental results of two-phase cooling have been obtained on a prototype and compared to conventional water/glycol cooling high-power electronics modules, with a considerable improvement on working temperature, power transfer capacity, and equalization of die temperatures during a full driving cycle. These results suggest that two-phase cooling using the same cold plates as in single-phase cooling can be used to substantially improve the performance and reliability of electric vehicle power converters without major changes.