| Title |
A Study on the Harmonics Effect of Ratio Differential Relay for Transformer Protection |
| Authors |
Kyung-Chul Kim ; Young-Rok Hwang ; Hun Kho ; Dong-Won Jung ; Hae-Sung Chung ; Dong-Wook Lee ; Chae-Ho Jeong ; Jae-Yoon Lee |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2014.28.6.099 |
| Keywords |
Transformer Protection ; Ratio Differential Relay ; Harmonics ; Inrush Xurrent |
| Abstract |
Power transformers are applied throughout the power system to connect systems of different voltage to one another. Since a ratio differential relay offers high sensitivity in detection of internal faults in power transformers, it is widely used in the main protection system. The use of nonlinear devices such as rectifiers and other devices utilizing solid state switching have been increased in industry during recent years. For nonlinear loads, the load current is not proportional to the instantaneous voltage. This situation creates harmonic distortion on the system. The harmonic could differential relay misoperation if not recognized. This paper aims at analyzing and probing into the influences of harmonics on a ratio differential relay for power transformer protection. |