Modelling methodology and experimental verification of the permanent-magnet-biased saturation-based fault current limiter

Regarding the line-type permanent-magnet-biased saturation-based fault current limiter (PMFCL), flux leakage effect is introduced in the modelling scheme to justify and ameliorate the theoretical analysis. The research indicates that the current flowing through the external circuit and the flux through the saturated iron-core are two principal variables in combining the external circuit with the magnetic topology of a PMFCL. Equivalent models coupling both the electric and magnetic circuits are established, in which the PMFCL is considered as a controlled voltage source dominated by the flux through the iron-core. A macro-model for simulation is achieved with MATLAB/SIMULINK software and the wrap-to-zero module is presented to substitute the switch in the simulation model. Experiments are further conducted and are thereby compared with the simulation results, which have verified the effectiveness and the accuracy of the proposed modelling methodology.