Protection of Teed transmission circuit using a new directional comparison technique

This paper presents the extended study and application of a new directional comparison technique for the protection of a Teed circuit. In the scheme, the fault current transient detectors, connected to the CTs at each end of the protected Teed circuit, are used to extract fault generated transient current signals. The polarity of the fault generated transient current signal detected at each end is then sent over to the line remote ends through the communication link. Comparison between the polarities detected at each end will determine whether or not a fault is inside the protected zone. The fault generated signals under arcing faults and their associated high frequency signals have been particularly investigated in the paper. Simulation studies have been implemented by EMTP software in a 400 kV Teed transmission, and results show that the scheme is able to give correct response for the protection of a Teed circuit under various system and fault conditions