Chair Power Electronics and Electromagnetic Compatibility

Prof. Dr. Prof. h.c. Josef Lutz

Phone +49 (0)371 531 24220
Fax +49 (0)371 531 24229
josef.lutz@…

http://www.tu-chemnitz.de/etit/le/index.php.en

Main research topics

The main focus of research lies on power device ruggedness and reliability. IGBTs are investigated regarding their overload capability esp. in short-circuit events, including possible measurements for improvement. Freewheeling diodes are improved regarding reverse recovery and dynamic avalanche, new structures are developed. Devices of Wide Bandgap materials (SiC) are analyzed regarding robustness. Failure mechanisms in device packages are identified by power cycling (10 test stations) and models for lifetime prediction are derived with the help of electromechanical simulations. Methods for online state of health analysis are developed especially for electric vehicles.

Extended description of Research topics

The professorship of Power Electronics and Electromagnetic Compatibility covers basic research as well as application oriented research in cooperation with industry partners Infineon, General Electric, Siemens and Mitsubishi. Three main research areas are:

1) Power Semiconductor Devices: This area of research focuses on robustness and ruggedness of power devices at overload conditions and at the edge of the safe operating area. It includes dynamic avalanche effects in silicon devices, short-circuit ruggedness of diodes and IGBTs, surge current capability of diodes and IGBTs. Research on SiC devices is supported by the European Union in the Framework of ENIAC/ERG.

2) Packaging Technology and Reliability: This area of research investigates the reliability of modules as well as of discrete power semiconductor packages. A part of the work is supported by ECPE Engineering Center for Power Electronics. 10 power cycling stations from 100 A up to 2000 A have been built. In parallel, the system analysis based on thermal and thermo-mechanical FE-simulations is executed and models for failure mechanisms are derived. HTRBand H3TRB tests for the evaluation of different packages are performed. One part of the work is supported by ECPE Engineering Center for Power Electronics, one part by the Norwegian Research Council, and one part by the German Research Society.

3) Electro Mobility: In the European project COSIVU (compact, smart and reliable drive units for fully electric vehicles) a SiC-based low-loss-low-volume inverter suitable for commercial electric vehicles is developed. The AdAnTe project deals with an IGBT based inverter with new methods for online state-of-health analysis. A further project is “showcase ELEKTROMOBILITÄT VERBINDET Bavaria-Saxony”, an academic education initiative for electromobility. The focus lies on the preparation, realization and evaluation of teaching modules on electromobility within workshops, summer universities and master courses.