Fault Detection and Identification of Three Phase Overhead Transmission Lines Ended with Underground Cables.

Elmitwally, A.; Mahmoud, S.; Abdel-Rahman, M.

doi:10.21608/bfemu.2020.124636

Fault Detection and Identification of Three Phase Overhead Transmission Lines Ended with Underground Cables.

Document Type : Research Studies

Authors

¹ Electrical Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., 35516., Egypt.

² Electrical Power Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., 35516., Egypt.

10.21608/bfemu.2020.124636

Abstract

In this paper, a scheme for fault detection and identification of thee phase overhead transmission lines ended with underground cables is proposed. Fault detection technique is based on mean square value of the difference between incoming and out going three phase currents of each section. Theses differences are compared against threshold setting values. Faulty phase identification is based on the analysis of three phase currents at one end of transmission line. The transient currents are processed by Discrete Wavelet Transform multi-resolution analysis. In order to find out the faulty phase, the absolute sum of the Wavelet Transform coefficients of the third level detail d3 of each phase current, corresponding to the frequency band 25-12.5 kHz, is computed over one cycle of power frequency. It is used as input to a Tule-base system to identify the fault type. Many case studies are provided to validate the proposed algorithm.

Main Subjects