dc.description.abstract |
The overhead power transmission system is a network of conductors that are used to carry power from
the generation station to the load side for most power plants around the world, including Ethiopia.
Fault detection, identification, and location in transmission lines are critical issues to increasing the
availability of power by reducing the time of interruption for maintenance in electric utility companies.
In this thesis, fault detection, classification, and location for power transmission systems using
artificial neural networks are developed for line-to-ground, line-to-line, line-to-line-to-ground threephase, and three-phase-to-ground faults in transmission systems. To develop this method, one of the
rural transmission lines in Ethiopia (Oromia, Gefersa substation to Fitche transmission line) is used as
a test line. This line is simulated using Matlab software to generate data for different fau lt conditions
with different fault locations and types, which are the fault phase voltage and current. The generated
data is preprocessed and put as an input for the neural network to be trained. MATLAB R2018a's
neural network toolbox was employed to train artificial neural networks (ANN). The feed-forward
multilayer network topologies of neural networks with improved back propagation and the LevenbergMarquardt learning algorithm were used to train the network.
After the network (8-10-1) was trained for fault detection, the mean square error performance,
regression plot, and error histogram analyses were made and found to have excellent performance with
a regression coefficient of 1, validation performance of 1.6191e-23, and an error histogram range of -0.025 to 0.025. And the network (8-10-5) was trained for fault identification and location, followed by
analyses of the mean square error performance, regression plot, and error histogram analysis the
results showed to excellent performance with a regression coefficient of 0.98094, a validation
performance of 0.010732, and an error histogram range of -0.056 to -0.006. Finally, it was found that
ANN is one of the alternate options in fault detection, identification, and location design for
transmission systems where sufficient transmission network data are available with a narrow fault
location distance range from the substation. This provides significant benefits in assisting with the
maintenance plan, saving efforts in fault location finding, and having economic benefits.
Keywords: Fault detection, fault classification, fault location, neural network, transmission line,
Matlab/Simulink |
en_US |