Transient behavior of static Fault Current Limiter in distribution system

Continuous growth of electrical energy demand and expansion of electric distribution systems has resulted in a corresponding increase in fault current levels in distribution systems. The protection of legacy equipment and continuous upgrading of feeders is both expensive and often impractical. Effective fault current limiting has thus become a critical factor. This problem may be partially solved by deploying Fault Current Limiters. This paper investigates the behavior of a Static Fault Current Limiter (SFCL) installed in a simple radial distribution grid simulated by Electro Magnetic Transient Program (EMTP). In order to integrate the SFCL into power grids, and because one of the problems concerning power semiconductor current limiters is the stress imposed by transients and the impact on sensitive loads; it is required to predict the behavior of the switching transients when fault occurs and switching actions take place. The results demonstrate how the SFCL can rapidly limit the fault current to an acceptable limited value. Simultaneously controlled turn OFF signals are initiated by the controller in order to mitigate the possible stresses produced by switching actions. Though, some of the disadvantages of using a SFCL are the cost and continuous power loss.