Mitigating the impact of distributed generation and fault current limiter on directional overcurrent relay coordination by adaptive protection scheme

Abstract

Overcurrent protection principle are mostly coordinated offline according to maximum load and fault currents on dominant topology. However, the traditional networks have been evolving gradually toward reliable and sustainable Smart Grid (SG) in which Distributed Generation (DG) (whether its coal based or renewable) is a vital component. Challenges have come along with advantages of DGs on protective relays such as coordination loss, which leads to several researching proposals to mitigate the impacts of DGs in modern networks. One of the many is the use of Fault Current Limiter (FCL) to lessen DG impacts, but since FCLs come with high cost to completely restore protective relay performance. Adaptive Protection Scheme (APS) exploiting the advance features of SG appear as an efficient solution to confront new challenges related to DGs and FCLs. The impacts of DGs and FCLs before and after employing APS are presented using the interconnected 6 bus system. Results have shown that APS can adequately integrate both DGs and FCLs with no adverse effects.