Validity of power cycling lifetime models for modules and extension to low temperature swings

Various papers in power electronics contain a part of lifetime estimation depending on power cycles in application. The used model is often the CIPS08 lifetime model published at the conference CIPS 2008. In many applications, a lot of cycles with low temperature swings occur. The used model, however, is only valid for temperature swings above 40 K. For temperature swings < 30 K, there are strong deviations, since some materials are now approaching the elastic region. First experimental power cycling results are gained below 30 K temperature swing. Also an approximation for the reliability of low temperature swing is given in this paper.