الفهرس | Only 14 pages are availabe for public view |
Abstract Typically, arcing fault conditions have negative impacts on the reliability of regular distance relays. This thesis conducts the development of a distance relaying scheme which is capable of protecting efficiently transmission lines that are subject to arcing faults. The study system is simulated using MATLAB/Simulink program with particular concern to arcing fault modeling. The developed scheme depends on collecting voltage and current signals from one-end of the line at a rate of 128 samples per cycle. The fault distance estimation problem is formulated, through discretization, as a set of simultaneous difference equations. Data windows of different sizes and locations, with respect to fault occurrence, are used to find the ~ most suitable. The different sampling mechanisms used in this research aid enriching the modes of solution of the problem. Two techniques are used for the solution of the problem; least square error method and simulated annealing method. These techniques are applied to two study systems. The first system is . . a 400kV transmission line from the literature. The second system is a part of the 220kV Egyptian network. The simulation study is applied at different fault locations of the studied systems. The obtained results prove the superiority of the simulated annealing - base distance relaying scheme as compared to the least square error relay. The preferred distance relay scheme, which yields the best performance, is based on the data collected during the first half cycle of the fault occurrence. This leads to a high speed distance relay response having 10 ms delay. The obtained results prove the effective impact of fault induced transients in estimating accurately the fault distance. |