Design and performance analysis of single-phase pre-saturated core fault current limiters

The technology of a presaturated core fault current limiter (PCFCL) has particular importance due to its instantaneous limitation of the fault current in electric power grids and keeping its value below the ratings of the switchgear or circuit breakers with a reasonable safety margin. In this paper, a design methodology of single-phase, simple nonsuperconducting magnetic coils, PCFCL is proposed based on extensive electromagnetic time-domain finite-element simulations taking into account the relative performances of the constructive design parameters. These controlled finite-element simulations allow fine realistic details, such as the nonlinear magnetic saturation behavior of the iron core to be included, and studying the effect on general performance during dynamic reactions of the system. Moreover, the dynamic behavior of PCFCL is characterized in terms of steady-state voltage drop across its terminals, counter electromotive force induced on the dc coil terminals, and limitation factor of the fault current. Dual-core and single-core designs are investigated with a comparison of their ability of limiting the fault current. Results reveal that the dual-core design has superior performance than that of the single-core one. Finally, a design methodology flowchart has been proposed which depends on the extensive simulation results of different PCFCL topologies and published experimental results, where changing either the governing constructive parameters or the magnetic iron core design are considered.