The High Température Superconductors discovery in 1986, and their improvement now allow to use their in Electrical devices. It is important to know their electromagnetic behaviour and especially their A.C losses. In this aim a numerical model (based on finite éléments) was developed in FLUX3D. In this model, superconductors are supposed to be perfectly non magnetic and the electrical field versus current density is a power law. For the moment, this law is independent of magnetic induction. Différent formulations ( Â, 9A/3t, T ) hâve been studied and compared, in order to impose an exteraal field, a transport current or to include a superconductor in a circuit. The numerical model has then been used to produce quantitative and qualitative results. Numerical, analytical and expérimental studies hâve been performed on a Bi-2223 OPIT strand in self field condition. It allowed to validate the classical hypothesis of perfect coupling between filaments, and has been a means to better understand the electrical measurement method. A two layers coil has then been studied and an analytical model for n layers coils was proposed. The studies presented in this report hâve also permitted to discuss the Bean model validity. Limitations of a power law with a critical current independent of magnetic induction and température hâve appeared too.
