Abstracto

GENERAL APPROACH FOR INTERNAL FAULTS REPRESENTATION OF THREE-PHASE THREEWINDING TRANSFORMERS IN EMTP-ATP

Mohamed A. Abd-Elaziz , Ebrahim A. Badran , and Mohamed M. I. El-Shmoty

Transformers are one of the most important elements in power system. Most of transformers are equipped with protection systems to avoid their damage. As the transformer outage has severed technical and economical consequences for the network, so implementing fast relaying algorithms is a challenge. Therefore, modelling of various types of internal transformer faults is the objective of this study. This paper introduces a proposed approach to model internal incipient winding faults in three-phase three-winding transformers using EMTP-ATP. The User Specified Object (USO) is used for building the transformer model under fault conditions. The proposed model have the ability to change the transformer impedance matrices in a simple manner to satisfy the internal fault conditions. The internal faults in the three-windings are simulated and tested. The results show that the proposed approach is able to represent the internal faults in the three-phase three-winding transformers accurately.