Impact of smart subtransmission level fault current mitigation solutions on service reliability

Superconductive fault current limiters and substation automation systems are two major smart grid technologies that can be directly or indirectly used for mitigation of high fault current levels at subtransmission systems. In comparison to the other conventional fault current mitigation solutions, it is expected that these solutions have much less negative impacts on the service reliability. This paper aims to quantitatively evaluate how these smart fault current mitigation solutions may affect the major attributes of the service reliability. Sustained interruptions, momentary interruptions and voltage sags are considered as major events that might appear in the electricity service of the customers due to a typical short circuit fault on the subtransmission systems. A typical Finnish subtransmission system is utilized in this paper for directing the quantitative reliability case studies. The study results show that in addition to the fault current mitigation aspects of the targeted solutions, their possible impacts on the service reliability should also be taken into account. (C) 2012 Elsevier B.V. All rights reserved.