At the Faculty of Engineering and Science, Department of Energy Technology (www.et.aau.dk) a PhD stipend within the general study program "Energy Technology" is open for appointment from November 1, 2012. The Department of Energy Technology is an expanding department covering most fields of Energy Technology ranging from electrical energy, power systems, power electronics, electrical machines to thermal energy including energy systems and fluid mechanics and combustion and also mechatronic systems. The department has about 150 employees - out of them are more than 70 PhD students. The laboratory-facilities are world-class and the research carried out is most often in collaboration with industry.


Stillingsbeskrivelse

The stipend is affiliated with the research Center of Reliable Power Electronic (CORPE) sponsored by The Danish Council for Strategic Research and hosted by Aalborg University.



The project will be carried out in close collaboration with Aarhus University, Aachen University, City University of Hong Kong and ETH in Zrich. The project also involves a close collaboration with the industrial partners Vestas Wind Systems A/S, Grundfos A/S, DanfossA/S and KK-Electronics A/S.

One of the most important components in power electronic circuits is capacitors which often cause failures in circuits. Voltage and temperature are typical device stress factors and failure study of both film and electrolytic capacitors are necessary. A detailed study of the physical layout as well as stability of the electrolytes should be included in order better to be able to explain and model the failures mechanism. Aging problems of isolation material should also be studied. Further accelerated test methods should be developed to test the usefulness of the models and also the degradation of the capacitors. This work includes also parameter estimation technique and testing of the capacitors for validation.

Expected results: To obtain better understanding of failure mechanism in capacitors and better life time models as well as accelerated test methods for capacitors.