Limiting fault current in a power system network by SFCL: A step input approach

Power system networks are growing and changing rapidly. The continuous increase in the interconnection of various grids to form a central grid and the ever growing power demand has led to an increase in fault current levels. This increase in the fault current has led to a simultaneous increase in the current interrupted by the circuit breaker also which makes it to break fault currents which are out of its rated breaking capacity. This paper utilizes a resistive model of a superconducting fault current limiter (SFCL) modeled in Simulink environment of MATLAB to mitigate this problem. The current limiting effect is achieved by an almost immediate transition of the HTS material from the superconducting state to a normal resistive state. A power system network is modeled and fault currents are observed with and without the SFCL model. Graphical simulations are also presented to show the effectiveness of the proposed model and the percentage reduction in fault current levels is also shown.