분산전원이 연결된 배전계통에서의 모델 기반 지락고장 위치 검출 방법

Abstract

In a distribution system with distributed energy resources, power flow is not fixed in a single direction. Therefore, from the protection coordination’s point of view, existing over-current protection scheme is not adequate any more. On the other hand, in future’s distribution systems, it is expected that various kinds of information is available with more accuracy, which is one of the advantageous points in protection. This paper suggests a novel fault location method with these factors considered. In the proposed scheme, an existing protective device like a recloser of fuse is replaced by a smart relay with simple calculation and communication ability. A distribution system is divided into several segments and the fault location is calculated through successive circuit analysis at each segment using concentrated parameters of the lines. In this, synchronized power data are assumed to be available at each loading point before a fault occurs and it is also assumed that each load is not changed abruptly. The suggested method is applied to several distribution system models, through computer simulations, and is verified to be useful with accurate fault location.