An Algorithm for Detecting CT Saturation

변류기 2차 전류의 포화 여부 판단 알고리즘

This paper presents an algorithm for detecting current transformer (CT). At the instants of beginning and end of saturation, the increment of the secondary current is reduced significantly, depending on the residual flux and saturation time. Thus, the third difference of the current is used to detect saturation in this paper. If the third difference is less than threshold the CT is at the beginning/end of saturation. The proposed detection method is unaffected by the amount of residual flux. The results of various tests with residual flux from -80% to +80% indicate satisfactory performance of the method.