EMTP implementation of the coupled electromagnetic-thermal problem of a magnetic shield type superconducting foult current limiter

In order to investigate the reciprocal interaction of a Superconducting Fault Current Limiter (SFCL) with electric networks a model of the device needs to be implemented in a simulation environment dedicated to power systems. the model should appropriately take into account all the relevant physical phenomena that affect the device behavior in a crucial way, including thermal effects and magnetic saturation. In this paper a circuit model of a magnetic shield type SFCL is presented. The model consists of three coupled non-linear electric, magnetic and thermal networks and is derived from an integral formulation of the coupled electro-magneto-thermal problem at the interior of the device. The implementation of the model in EMTP is also discussed. No "ad hoc" hypotesis, that would result in a loss of accuracy, are introduced for the sake of the implementation.