الفهرس 
ABSTRACT
Fault Location MethodsOnly 14 pages are availabe for public view
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Abstract
This thesis is aimed at estimating fault location on overhead transmission
line using two different approaches. The first approach is based on waves
originated at fault location. Faults in power transmission lines usually
cause transients that travel at a speed close to the speed of light and
propagate along the line as traveling waves. Traveling wave theory is
utilized in capturing the travel time of the transients along the line
between the fault point and the protective relay. This will help in
proposing a fault location technique based on high frequency components
of fault current. The resolution time for these components is provided by
discrete wavelet transform (DWT). The application of the proposed
technique for different fault types is illustrated using simulations obtained
by MATLAB Simulink program. The accuracy of the proposed technique
for locating the fault is assessed for different fault inception angles and
fault resistance values.
The second approach for fault location is based on nominal π-model
transmission-line representation. It solves the describing differential
equation for nominal π-model of line under different types of fault with
mutual inductances and mutual capacitances taken into consideration.
Sampling of the measured currents and voltages at relay location and
using central differences, the current and voltage derivatives can be
determined from the measured samples. Using adequate data window for
measured current and voltage, the line equation can be solved to
determine the line impedance from relay location to fault point and hence
ABSTRACT
- iii the fault location is defined. Least square error method is used to obtain
the best solution from the used data window. The application of the
proposed technique for different fault types is illustrated using
simulations obtained by ATP/EMTP program. The accuracy of the
proposed technique for locating the fault is assessed for different fault
inception angles and fault resistance values.
The proposed approaches are accurate in assessing the fault location and
have the advantages of being independent of the fault resistance and fault
inception angles under different fault types.