In order to plan the integration of superconducting fault current limiters (SFCLs) in power systems, accurate models of SFCLs must be made available in commercial power system transient simulators. In this context, we developed such a model for the EMTP-RV software package, a power system transient simulator widely used by power utilities. The model can be used with any resistive-type SFCL (rSFCL) made of high temperature superconductor (HTS) tapes, which are discretized in ‘electro-thermal elements’. Those elements consist solely of electric circuit components, and are used to represent portions of tape of various sizes and dimensions (a ‘multi-scale’ approach). Both the electrical and thermal behaviors of the tape are modeled, including interfacial effects, nonlinear properties of materials and heat transfer to the surrounding environment. Such a multi-scale model can simulate accurately both the local quench dynamics of HTS tapes (microscopic scale) and the global impact of the rSFCL on the power system (macroscopic/system scale). In this paper, the model is used to compute phenomena such as propagation velocity of a hot spot and heat diffusion through the thickness of the tape. Results were verified by comparing EMTP-RV results with finite element simulations. In addition to the development of the multi-scale model itself, which is the major contribution of this paper, the use of the model allowed us to determine the conditions of validity of the commonly used ‘homogenization’ of the thermal properties across the tape thickness. Indeed, when the current flowing into the rSFCL is slightly above its critical current Ic (and up to ), very important errors in the power waveforms arise, leading to potentially wrong decisions of protection systems. Homogenized thermal models should thus be used with great care in practice.

International audienceIn this paper, authors present a comparative study of inductive and resistive superconducting fault current limiters (SFCL) from current limitation and power system transient stability point of view. Different types of SFCL can be used to decrease the amplitude of fault current in a power system. The two most used are resistive type (rSFCL) and inductive type (iSFCL). However, no studies have been done to show the difference between them in term of current limitation and transient stability on a same power system. We propose here to compare rSFCL and iSFCL when a fault occurs in a simple high voltage (HV) power system (IEEE 3 bus test system). To evaluate the impact of SFCL in the studied power system, time domain approach is used to evaluate the short-circuit current in the electrical power system by solving the differential equations of such circuit configuration for various SFCL impedance. For the transient stability study, authors use an approach based on the equal area criterion to evaluate the critical clearing angle (CCA) and a time domain approach to evaluate the critical clearing time (CCT) for the two types of SFCL. Results show that the two SFCLs have different impacts on the power system. However, the resistive SFCL appears to be the more suitable to limit the fault current and to increase the transient stability of the power system in case of short-circuit