A Novel Five-Leg Design for Performance Improvement of Three-Phase Presaturated Core Fault-Current Limiter

In this paper, a novel five-leg design of non-superconducting, three-phase, presaturated core fault-current limiter (PCFCL) is proposed based on the time-domain, electromagnetic finite-element simulations to overcome the main drawbacks of the well-known topologies of PCFCLs. These drawbacks are large volume of magnetic iron core, high total power loss under steady-state condition, high-induced voltage across the dc coil terminals during the fault condition, and the technical risks of high-temperature superconducting coil and cryogenics in the case of superconducting fault-current limiter (SFCLs). The general performance of PCFCL can be expressed through the steady-state power loss and voltage drop, and fault-current clipping ratio and the induced voltage across the dc coil terminals during the fault condition. Different topologies of three-phase PCFCLs are considered with the comparison of their limiting capability for different types of faults. The results reveal that the proposed design of PCFCL has superior properties in limiting any type of fault currents with reduced volume of the magnetic iron core, total power loss, and the induced voltage across the dc coil terminals in comparison with those of the well-known dual-core PCFCL design. Furthermore, a performance analysis of the novel five-leg design is considered throughout an extensive simulation of the constructive controlling parameters to study their relative effects on the general performance of operation.