Nouvelle approche de modelisation de la branche de magnetisation pour la simulation des transitoires electromagnetiques

This work presents a new magnetizing branch model to simulate the hysteresis and saturation phenomena in a transformer. This new model, named the A(x) model, has been implemented for an electromagnetic transients simulation program, named EMTP-RV. The capabilities of the A(x) model include better precision and extended degrees of freedom to fit a large variety of curves, while maintaining computational efficiency. This model can be categorized as a rate-independent scalar model of ferromagnetic hysteresis with non-local memory.;Also, the theory surrounding the A(x) model is thoroughly explained and the details regarding its implementation in a numerical environment are refined. Furthermore, special cases of divergence, numerical oscillations, for instance, are examined and solutions are proposed.;The objectives of this project are to implement a new model that would be easily definable and to compare and validate it with other existing models. To do so, a few benchmarks are created, in order to assess the validity of the model under different scenarios. The results obtained from these tests are conclusive; the A(x) model is able to better reproduce the losses under steady-state conditions than other antisymmetric models and it is able to initiate ferroresonnance correctly when an open coupled circuit from a high-voltage double-circuit line is connected to an unloaded transformer. It is also computationally efficient and requires only the major loop data, which is more readily available data than the minor loops or first-order reversal curves.