Current Limiting Simulation of Magneto-biased Superconducting Fault Current Limiter (SFCL) Applied in 66kV/10kV Power Substation in China

The short-circuit fault current caused by the large transmission capacity poses a challenge to the stability and safety of the power system. Magneto-biased superconducting fault current limiter (SFCL)consists of a double-split reactor, a non-inductive YBCO component and a fast circuit breaker. In this SFCL, one branch of the double-split reactor is in series with the YBCO component and the circuit breaker, and then they are in parallel with the other branch of the double-split reactor. This proposed SFCL has the advantages of two-stage current limiting, self-triggering and self-recovery, which can effectively and reliably decrease the short-circuit fault current in power grids. This paper analyzes the operating mechanism of the magneto-biased SFCL and establishes a package type magneto-thermal coupled simulation model of the SFCL based on MATLAB/SIMULINK. The power system model of a 66 kV/10 kV Zhang Tai Zi Power Substation which is in Liaoning province in China has been established including a magneto-biased SFCL. It has 7 nodes in the transmission line, the total length of 5.08 km and the maximum transmission power capacity of 5.455 MVA. The SFCL is connected to the low-voltage side of the 66 kV/10 kV transformer. The operation performance of magneto-biased SFCL is theoretically investigated in three-phase short-circuit faults when SFCL is at different locations. The simulation results show that the maximum fault current limiting rate is 26.4% and the temperature of SFCL rises to 123.7 K, which validates the feasibility of magneto-biased SFCL applied in actual power substation.