Laminar impinging jet cooling for compact power electronic modules

Compact and highly-integrated energy supply devices challenge the applied storage and propulsion system’s thermal conditions. To warrant the system’s reliability and sustainability, it is crucial to ensure the temperature limits of battery, electrical motor, and power electronics by adequate cooling. This thesis investigates new heat transfer concepts with alternative cooling approaches based on single-phase impinging micro jet cooling, which use water as coolant. The aim is to evaluate the impinging jets’ potential to meet the rising demands that adhere to compact power electronics modules. A first aim is to investigate several heat sources that contribute to the thermal load of integrated power electronics modules such as diodes, MOSFETs, and IGBTs. Using thermo couples and infrared thermography surface temperature distributions of the semiconductors and hot spots of the power electronics modules are characterized. To cover a wide range of the developed cooling concepts, two particular layouts are investigated. The first part of the experimental and numerical investigations is based on a standard MOSFET-semiconductor applied to a printed copper board (PCB), which is a common power electronics module. Possible applications within the lower performance range up to maximum switching capacities of 10 kW. The second part of investigations consists of a direct bonded copper board (DBC) equipped with two diodes and one IGBT-semiconductor. It represents power electronics applications beyond 10 kW switching capacities. With respect to power demands numerical investigations characterize the pressure drop and the pumping power of the cooling concepts and enable a comparison to conventional cooling systems. Based on the achieved results of the developed impinging jet heat sink, the potential use in future power electronics applications is discussed. Further, analyses of the fluid dynamics and heat transfer characteristics are presented. A comparison of the cooling approaches efficiencies highlight their competitiveness. The final part of this thesis (Predictive Cooling) introduces a cooling strategy, which predicts the coolant flow rate in order to fully compensate hot spots of an IGBT-module, which is operated at transient conditions. Finally, the results of each cooling approach are summarized and an outlook will be presented.