Investigation of voltage quality improvement with coordinated applications of fault current limiter

This paper illustrates how the application of fault current limiters (FCLs) on distribution systems helps to enhance voltage quality at the distribution buses and minimise disturbances to loads, consisting substantially of electrical motors, during the occurrence of a fault. Since the major contributions to the number of disturbing sags, for a given equipment sensitivity level, are from the higher voltage levels, this paper also exploits the feasibility of adding FCLs to different subtransmission structures for sag mitigation and fault current reduction. The concept of “exposed area” will be used to express the reduction in the number of disturbing sags with FCLs installed