A new intelligent auto-reclosing method considering the current transformer saturation

摘要

In this paper an intelligent method of the auto-reclosing (AR) function is presented. The presented method comes to a decision whether or not an AR could be done based on the flux calculation of the current transformer (CT). One advantage is that this allows increasing power quality by enabling the AR function without additional costs for oversized CTs. Another important advantage is, that with this method costs could be saved at the dimensioning of new CTs. It is shown, that only one additional relay parameter is needed for setting the new intelligent AR function. The calculation of this parameter is based on rated values for class P protection CTs and the operating burden. The application of the presented method is explained for medium voltage networks. Considering the changes in the structure of the power system caused by the deregulation the advantages of using the AR function are presented.