Under the motto "Robust Power Electronics for Drive and Energy Technology," the research work at the Chair of Power Electronics and Electrical Drives is conducted.

Power Semiconductors

The core competency of the chair lies at the interface between power semiconductors and converters. Profound knowledge and experience exist in both the semiconductor-physical processes in power electronic components and the requirements of high-power converters. Building on this, scientific questions related to the short-circuit behavior of IGBTs, the influence of charge carrier dynamics on the switching behavior of IGBTs, the fault behavior of power semiconductors, the control of reverse-conducting IGBTs, hybrid switches consisting of Si-IGBTs and SiC-MOSFETs, and the use of SiC-MOSFETs in high-power converters are being addressed.

For tackling these tasks, test benches for the electrical and thermal characterization of high-blocking power semiconductors are available, reaching voltages up to 5kV and currents into the double-digit and for fault studies, also into the triple-digit kA range. Component simulation is carried out using modern FEM programs, where the combination of simulation and measurement technology provides a deeper understanding of the processes in the power semiconductors and the interaction with the circuit environment and the control circuit.

Converter Control

The knowledge of the Chair of Electrical Energy Supply and the Chair of Power Electronics is combined for researching the control of grid-connected converters. Control concepts for HVDC-coupled offshore island grids and for grid-forming control of wind turbines and multiterminal HVDC systems are being developed. The influence of loads on the stability of the interconnected grid is also being investigated.

The expertise of the chair in power semiconductors, converter hardware, and control concepts is bundled in the research of particularly multipoint converters with and without a central DC link, their control and regulation, and fault behavior. Modular multipoint converters, three- and five-point converters, parallelized two-point converters, and current-source converters are addressed.

For control-related questions, an extensive model grid with numerous converters of low power but high-performance control, doubly-fed asynchronous generators, synchronous generators, various loads, and power-electronic grid simulations is available and continuously being expanded.