AN ADAPTIVE APPROACH FOR DISTANCE PROTECTION OF POWER TRANSMISSION LINES

Abstract

The author in this report presents the development of adaptive distance relay and its. real-time simulation. The Relay includes adaption against fault in series capacitor compensated line that identifies the location of fault with respect to the installed series capacitor and takes appropriate action to make the relay to look the fault in the correct zone. It takes care of circuit breaker failure by providing the backup protection by issuing trip signal to• the upstream circuit breaker in the case of main breaker failure condition. And it describes its adaptiveness in close in fault conditions where polarising voltage to the relay collapses to a very small quantity. These adaptive features have been developed along with the normal distance protection. The distance relay model has been built using MATLAB environment. A Real-Time hardware setup has been described which has been prepared in the Power System Laboratory at IITR for testing the Relay at different conditions as stated above. The control of the power circuit has been done using the control circuit developed by the author. The series capacitor has been installed in the line which checks the adaptiveness of the relay in case of fault including the series capacitor in the fault loop. Also a power system model has been created in the Matlab/Simulink for verifying the results of the real time simulation and testing the relay against the cases which is not possible to simulate with the real time setup