Compact DC-AC SiC Inverter for High Ambient Temperatures in Hybrid Electric Vehicles- ETH Zurich Power Electronic Systems Laboratory

Compact DC-AC SiC Inverter for High Ambient Temperatures in Hybrid Electric Vehicles
 Power electronic converters are key components of Hybrid Electric Vehicles, which are in the core focus of the Research and Development activities of the automotive industry. Today’s converters feature Silicon power semiconductors with a junction temperature limit between 150 °C and 175 °C and thus their operating ambient temperature range is limited to values typically well below 80 °C. This implies undesired restrictions regarding cooling circuit requirements or the placement of the converter due to the ambient air temperature level in case of air-cooled converters.Silicon Carbide (SiC) power semiconductor switches allow to increase the junction temperature beyond 175 °C and thus to overcome the above mentioned restrictions. In this research project, an ambient-air-cooled, high power density SiC inverter system for an ambient air temperature level of 120 °C is investigated. In order to be able to fully utilize the semiconductors, the converter is designed for an optimum junction temperature of 250 °C. A high switching frequency of 50 kHz keeps volume and weight of passive components low and covers a broad range of output frequencies suitable even for driving high-speed electrical machines. It is made sure that the individual devices are operated within their specified temperature ranges by carefully choosing the component placing taking needs from an electrical point of view into account and by active Peltier cooling of the components. Some components, such as high performance fans for the air-cooling system, are currently not available on the market in the required temperature range and thus are developed as an additional part of this project. All obtained results are experimentally validated on a test high speed test bench with a 10 kW permanent magnet synchronous machine and an induction machine rotating up to 30’000 rpm.
 Power Electronics Systems Laboratory DC-AC Converters
 Dr. Benjamin Wrzecionko  Contact ETH Zurich Power Electronic Systems Laboratory Physikstrasse 3 ETL H23 8092 Zurich Switzerland

LINK
https://www.ethz.ch/content/specialinterest/itet/power-electronic-systems-lab/en/research/research-and-thesis-projects/dc-ac-converters/DC-AC-Converters-1.html