  Power loss estimation is an indispensable procedure to conduct lifetime
prediction for power semiconductor device. The previous studies successfully
perform steady-state power loss estimation for different applications, but
which may be limited for the electric vehicles (EVs) with high dynamics. Based
on two EV standard driving cycle profiles, this paper gives a comparative study
of power loss estimation models with two different time resolutions, i.e., the
output period average and the switching period average. The correspondingly
estimated power losses, thermal profiles, and lifetime clearly pointed out that
the widely applied power loss model with the output period average is limited
for EV applications, in particular for the highly dynamic driving cycle. The
difference in the predicted lifetime can be up to 300 times due to the
unreasonable choice the loss model, which calls for the industry attention on
the differences of the EVs and the importance of loss model selection in
lifetime prediction.
