Evaluation of the Performance of Different Relays under Magnetizing Inrush Current.

Kandil, Mahmoud Saber Ahmed; Ahmed, F. I.; El-Tamally, H. H.

doi:10.21608/bfemu.1980.182457

Evaluation of the Performance of Different Relays under Magnetizing Inrush Current.

Document Type : Research Studies

Authors

¹ Assistant Professor, Electrical Engineering Department, Faculty of Engineering, Mansoura University, Mansoura, Egypt.

² Professor of Electrical Power & Machines Department, Faculty of Engineering, Cairo University, Egypt.

³ Demonstrator, Electrical Engineering Department, Faculty of Engineering, Ilmenia University.

10.21608/bfemu.1980.182457

Abstract

Harmonic restraint differential relays are popular in practice for transformer protection. Under magnetic inrush current, these relays should not operate since the harmonic restraint discriminates between this current and short-circuit current according to the harmonic analysis of the two waves. This analysis is carried-out for different operating and design parameters of the protected transformer. The resulted data is used to evaluate some practical differential relays with harmonic restraint. A new idea for a restraining feature of differential relay is of introduced.

Main Subjects