Ce document numérisé est le fruit d'un long travail approuvé par le ...

Abstract
In the field of a reliability study on power electronic components dedicated to electrical
traction, the identification then estimation of the thermal constraints generated during
operation are very important. Indeed, with their repetition over the time, they induce a thermal
fatigue, which consequence is the material damage of the component. This phenomenon leads
to an evolution of the electrical and thermal characteristics of the power modules and appear
as one of the major causes of failure listed for electrical traction where thermal cycling
constraints are severe.
After done astate of the art of the components used in the electrical traction and formulate the
theoretical basis required for the comprehension and the resolution of the problematic, we
focused to estimate the lGBT power module lifetime used in an automotive hybrid vehicle.
Thus, after a recording, with an original method with optical fibres, the chips temperature on a
vehicle in operation in an urban traffic, then an identification of thermal cycles with a
statistical method of the temperature distribution, we have done sorne power cycling tests
with the intention of estimate the module lifetime under different constraint levels. Finally,
with a correlation ofthese two tests, we've been able to estimate the strong presented by these
modules versus the repetitive of the thermal constraints generated and reinforce the
automotive manufacturers in their request of the lifetime.
Finally, we have focused on the estimation of the thermal constraints generated, first, in
DUAL module, with an unidimensional Re mode!. Then, with the use of a model taking into
account the thermal interactions between chips, we have looked the case of the multichip
integrated converters. In this last study, the model has been validated experimentally on a
hybrid traction line and allows us to obtain thermal constraints generated in real operation
conditions on a normalised European road mission profile. Finally, with this study, we have
shown the possibilities of this tool in the supervision and prediction of the thermal constraints
during operation of the integrated power converters.