PhD candidate for developing multi-physics models of high-power medium frequency transformers

We are looking for highly motivated individuals with an outstanding academic background who are interested in pursuing a PhD in the important and multidisciplinary research area of modelling and optimising high-power, medium-frequency transformers (MFTs). Compact, highly efficient transformers that operate at kilohertz frequencies are key components of high-power DC-DC converters, which are the core component of solid-state transformers (SSTs). Such SSTs are required, for example, in future AI data centres, where power consumption per computer rack increases to levels of several hundred kilowatts or even megawatts. To transfer energy efficiently from the grid to CPUs/GPUs, higher system voltages are required in data centres/computer racks, and efficient power electronics converter systems based on SSTs are essential for controlling the highly dynamic power flow.

For pushing the efficiency and power density limits of these SSTs you will develop multi-physics models of transformers, which describe not only the (HF) losses in the winding and the core, but also the cooling/temperature distribution in the transformer, resonances in the winding due to parasitic capacitances, and electrical insulation. You will also work on optimising the core and winding geometry, developing advanced cooling concepts for the windings and core, and designing solutions for efficiently connecting the high-current windings. Using the models and concepts developed, you will then identify technological barriers to the transferable power and efficiency of MFTs.

The developed models should be integrated into optimisation procedures for power electronic converter systems in a computationally efficient way. This is essential for achieving outstanding system efficiencies and power densities, as well as gaining a competitive edge. The models are also part of an ongoing, wider modelling framework development project at HPE, offering the opportunity to collaborate with other PhD candidates on different modelling aspects.

For verifying the new concepts and developed models, you will design and build MFT prototypes, including converter systems, to operate the MFTs under realistic conditions.

• You must have a diploma/M.Sc. degree in electrical engineering with excellent grades
• Fundamental knowledge of power electronic converter systems
• Good communication skills
• Fluency in English
• The willingness to fully commit yourself as part of an international team.
• In addition, you should be interested in the detailed modelling and design of magnetic components and the optimisation of power electronic systems.