ZONE PROTECTION SYSTEM OF TRANSMISSION LINE BY DISTANCE RELAY

Abstract

In this thesis design and modeling of Distance Relay has been done using MATLAB-SIMULINK. When microprocessor technology was implemented in the relay designing technique it gave birth to a new type of protection methodology known as Numerical relay. Numerical relays can interact with the peripheral devices and other numerical relays also, resulting in overall economy of the protection system equipments. A power system network and the distance relay model has been developed and the response of the distance relay has been verified by plotting the data generated by the relay on R-X diagram. The input voltage and current signal from the power system network contains dc offset values and higher order harmonics these are the unwanted quantities of the signal which need to be filtered out for proper functioning of the relay, Discrete Fourier Transform (DFT) can easily isolate these unwanted quantities from the signals. DFT has been used for the designing of the proposed distance relay. This report tells about the necessities of this relays in a power system and why these are so important for generator only and why not for others. This model in Simulink is treated with different types of faults such as line and ground fault. This report also tells about the brief discussion about the excitation system relating to the generator protection and coordinating with other devices.