Defaults in Laminations (Défauts dans des tôles, Programme Hubert Curien 2018 n40707TF) (DEFOTOL)

Many electrical devices comprise laminated magnetic circuits, both for household appliances and industrial applications. The most common are electrical machines and power transformers, less known to the general public. Nowadays, there are more and more environmental constraints, new regulations that require high performance and energy efficiency for these devices. It is therefore essential to be able to diagnose, control and assess the impact of possible faults on their performance and ensure their operation.

Numerical modeling allows the analysis of faults and their dynamics. Among these faults, the insulation faults between the ferromagnetic laminations may generate significant overheating which can cause the destruction of the magnetic circuit. Due to its multi-scale nature, it is very difficult to numerically model this phenomenon in 3D with affordable memory resources and computing time. Thus, to overcome such problems, we envisage to couple homogenization techniques which globally models the healthy parts of a device with a fine model taking into account local phenomena due to insulation faults. In the literature, simplified 2D models have been developed by this approach. The goal of the project is to model in 3D several short-circuit faults and to establish, from this fine and precise modeling, a reduced model (Model Order Reduction or equivalent diagram type) of an electrical device which account for faults in order to study this device in its environment.