Enhanced lifetime and power-cycling modelling for PrimePACK(TM) .XT power modules

In this paper, the modelling strategy for the Infineon .XT power-cycling diagram is discussed. To that end, power-cycling tests at high temperature swings are performed supplemented by three-dimensional thermomechanical simulations over the full temperature swing regime, which offers the possibility to extrapolate the power-cycling diagram towards lower temperature swings. The cycle counts until the end of life has increased compared to the previously published .XT power cycling diagram, and additionally a ton-dependency can be defined, which takes the duration of load pulses into account. Owing to these updates, the predicted lifetime of .XT power modules in the application is significantly increased. This benefit for the lifetime prediction is illustrated as an example based on a wind turbine mission profile.