New structure of nonsuperconducting fault current limiter for wide ranges of currents based on PWM switching strategy

A new structure of nonsuperconducting fault current limiter (NSFCL) is proposed in this paper. The structure is capable to control the magnitude of wide ranges of fault currents due to consumer choices. In order to control the magnitude of line current, four similar resistors which bypassed by semiconductor switches are in series with the reactor in the DC bus. The proposed circuit is not only capable to be used in wide ranges of fault currents, but also reduces voltage stress across switching components. Furthermore, low voltage semiconductor switches have lower conduction losses and the implementation cost is less than previous presented (NSFCL) topologies. These features can be counted as economic advantages of the proposed structure. The simulation results are provided to clarify the novelty of the circuit.