Thermal Management based on Flat-Plate Pulsating Heat Pipes for Power Modules of Electric Powertrains

The thermal management of power electronics is a critical challenge for the successful electrification of mobility. To satisfy the strict weight and efficiency requirements realizing a highly integrated cooling system is crucial. In this context, flat-plate pulsating heat pipes are a promising technology, adding a passive thermal functionality to thin mechanical structures. To evaluate potential applications within the inverter, a numerical 3D-model based on thermal conduction is employed. The present modeling approach is derived from considerations of thermal resistances in flat-plate pulsating heat pipes adapted to well documented experiments from literature. The thermal performance of concepts utilizing the pulsating heat pipe is compared to a conventional solid design. The benefits of heat spreading to a continuous heat sink and the transfer to remote heat sinks are investigated. In addition, an innovative double-sided cooling approach is presented, which combines the benefits of traditional heat spreading with the remarkable thermal conductivity of the heat pipe from the top side. The results are highlighting the new degrees of freedom in thermal management which are enabled by flat-plate pulsating heat pipes.