Multilevel Nonsuperconducting Fault Current Limiter: Analysis and Practical Feasibility

A new topology for nonsuperconducting fault current limiter (NSFCL) based on multilevel switching strategy is proposed in this paper. The proposed multilevel NSFCL circuit aims to control the high-level fault current by inserting different resistances in the circuit. Due to interrupting the fault current based on multilevel switching strategy which results in the decrement of switching numbers, power loss will be reduced and lifetime of the utility devices will be increased. The proposed NSFCL structure has the capability of limiting the fault current based on obtained quantities from current sensors. The proposed NSFCL topology which has no effect on voltage and load currents of the utility, ensures a high level system protection. The analysis of normal and fault conditions of the proposed multilevel NSFCL have been provided and experimental results are demonstrated to prove feasibility of the proposed structure.