State of art of fault current limiters and their impact on overcurrent protection

Due to increasing fault current levels in transmission and distribution level, considerable attention is given towards developing fault current limiter (FCL) devices in recent years. Most of the FCL technologies are in their initial stages of deployment and are being assessed before their use become more widespread. As the objective of FCL is to limit the fault current, it will have impact on protection system. This paper gives an overview of the different FCL technologies, improvements made in FCL devices and assesses their impacts on overcurrent relay protection. An analysis on overcurrent relay operating time and therefore co-ordination has been presented based on the results obtained from a network splitting model developed using PSCAD/EMTDC.