| Title |
Discrimination Method of Internal and External Fault of Current Differential Relay using Instantaneous Value of Current in Case of Fault with One end CT Saturation |
| Authors |
이명희(Lee, Myoung-Hee) ; 최해술(Choi, Hae-Sul) ; 김철환(Kim, Chul-Hwan) |
| DOI |
https://doi.org/10.5370/KIEE.2012.61.12.1801 |
| Keywords |
Current differential relay ; CT saturation ; EMTP ; External fault ; Internal fault |
| Abstract |
This paper presents a simple and practical method which enables to prevent malfunction of protection relay due to differential current caused by one end CT saturation in case of external fault. This method uses difference of magnitude(instantaneous value) between the both end current just before the occurrence of differential current without a separate method to CT staturation detection. One end CT saturation is simulated by current transformer model using type-96 component and the presented method is verified by using EMTP MODELS with respect to internal and external fault with one end CT staturation. The presented method distinguished rightly bewteen external and internal fault with one end CT saturation. This information can be used to prevent malfunction of current differential protection relay in case of external fault. And this method is not affected by sampling rate and has no calculation burden, so it will be applicable to differential current protection relay with ease. |