An Approach for Differential Protection of Transmission Lines

Abstract

Throughout the history of power system protection, researchers have strived to increase sensitivity and speed of apparatus protection systems without compromising security. In this research work, mainly concentrated on transmission line protection for different topologies submitted to various fault conditions. Firstly, literature review on the existing approaches for the protection of transmission lines related to distance protection and current differential protection has been carried out. Then, study on fault analysis for different topologies like single transmission line and parallel transmission line systems is carried out using matlab/Simulink®. For these two topologies, existing approach in which information of current phasors(i.e. PMR and PAD) and proposed approach of current differential protection(using DC offset component information) are implemented. Results and observations from simulations carried out on matlab/Simulink® and PSCAD are presented and these two approaches are compared to verify reliability of proposed approach. Finally, some suggestions to future work are mentioned