Transient dynamic analyses of presaturated core fault current limiters through flux and inductance versus current modelling

Abstract

Here, the outcomes of experimental measurements and finite-element simulations are used to develop MATLAB/Simulink models for evaluating the transient dynamic behaviour of the well-known dual-core presaturated core fault current limiter (PCFCL), either for single- or three-phase configurations. These models are based on calculating the total flux linkage–current characteristics of the AC coils at different levels of DC biasing current, taking into consideration the induced voltage across the DC coil terminals due to significant flux variation during the fault condition. On the other hand, the time-varying self-inductance and the self-inductance–current characteristics of the PCFCL are directly developed through Simulink modelling. It is worth mentioning that the self-inductance–current characteristic enables an important and quick design optimisation tool for PCFCL, where the dynamic inductance term significantly contributes to the total voltage drop across PCFCL in comparison to the static inductance. These total flux linkage and inductance versus current models can be directly used for modelling the dynamic transient behaviour of PCFCL when attached to any electrical transient programme used for analysing complex electrical power systems, with remarkable accuracy, quicker, and easier for various network scenarios and fault conditions.