PA – Mission profile simulation of cryogenically cooled power modules in fuel cell electric aircraft

Highly efficient aircraft architectures with superconducting cables and motors and cryogenically cooled power electronics are crucial for (more) electric air travel. But low temperatures pose significant thermo-mechanical challenges for power modules. Therefor the lifetime of the power modules needs to be validated in active power cycling tests. For the design of an application relevant test the knowledge about the thermal stress of the power modules in the application is needed.
In this project thesis a simulation for a system consisting of a basic B6-inverter with GaN-HEMTs and a typical electrical motor for electric aircraft should be developed. The simulation should take a mission profile from literature as an input and output the resulting thermal profile of the switches, assuming cryogenic cooling in liquid nitrogen. To achieve this the modelling of the GaN-HEMTs at cryogenic temperatures needs special attention, since supplier models typically do not cover this temperature range. Furthermore, the thermal modelling of the heat transfer to the liquid nitrogen is complex to describe and needs specific solutions. Since both modelling problems are highly complex, a worst-case- and best-case estimation of the appropriate values is
sufficient. Models should preferably be analytical and be implemented in such a way that they are easily replaceable in the simulation.
Optionally, to round of the work, the extraction of the occurrences of relevant temperature swings via rainflowcounting can be done.

Bearbeiter: Musa, Muhammed

Betreuer: Lukas Farnbacher (IISB), Jordan Sorge (IISB)

Verantwortlicher:  Prof. Dr.-Ing. Martin März