PROJECT TITLE :

A PMU-Based LOE Protection of Synchronous Generator in the Presence of GIPFC

ABSTRACT:

The existence of a generalized interline power-flow controller (GIPFC) within the transmission lines changes the voltage and current signals that are measured with the protection relays of power system dynamically. In this paper, the results of the GIPFC on the measured impedance by the loss of excitation (LOE) relay of the synchronous generator are initial investigated by analytical and computational ways for different operating modes of the power system. The results indicate that the presence of GIPFC causes a substantial delay on the operation of the LOE relay. It is conjointly shown that when partial LOE occurs, the GIPFC causes to the LOE relay underneath-reaching. Consequently, to readjust the relay in the presence of the GIPFC, a new modified LOE protection algorithm on the basis of synchronized phasor measurements received from phasor measurement units is presented. The most necessary advantage of this modified algorithm is that it is a general algorithm that considers all voltage-source-converter-based versatile ac transmission systems controllers. Relating to the simulations results, it is concluded that using the modified algorithm for the LOE relay will sufficiently decrease the delay and forestall the relay from beneath-reaching. The impacts of the unified power-flow controller and interline power-flow controller on the LOE relay also are demonstrated.