الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The temperature of overhead transmission line is an important factor in designing the current capacity of these lines. The transmission capacity of an overhead line has always been an interesting subject for utilities. The available transmission capacity is determined to a large extent by the actual overhead line conductor temperature. Many researches have considered the relation between the temperature and the ampacity of the transmission line T.L. Some methods were developed in this field such as statistical methods, numerical methods, real time thermal rating system...etc.
In this thesis, the radial temperature distribution of a transmission line sample is calculated for different loads, line dimensions, and ambient condition, by utilizing the heat diffusion equation in conjunction with heat balance equation in calculating the surface and inner temperature of a transmission line taking into account the boundary conditions at the inner and outer radius of the transmission line.
Due to the presence of the T.L junctions, a mathematical model for these junctions must take place to get the inner and outer junction temperature for different loads, dimensions, and ambient condition, which have a great effect on power system reliability and continunity of power transmission where the junctions are considered as the weak points that must be taken into consideration.
A practical data is measured and collected from working substation for junction of a transmission line for different loads, and it is compared with the calculated results from the mathematical model results for the same load, junction dimensions, and ambient temperature.
The heat equations method has some difficulties. These difficulties include complicated calculations of many equations, such as the heat diffusion equation heat balance equation and heat rate equations including the boundary conditions, which make errors in calculating the temperatures of transmission lines and junctions.
Artificial neural network ANN model is proposed as a new, accurate, and simple technique to determine the temperature of transmission lines and junctions. The artificial neural network model is trained by the output data from the conventional method to get general model for transmission lines and junctions. These models are suitable for determining the temperature of any overhead transmission line and junctions with any dimensions, loading and enviromental conditions. It is found that the artificial neural network model is accurate especially in predicting the temperature of T.L. with the data that not included in the training process. This is useful in using the artificial neural network model in the practical prediction of temperatures of transmission lines and junctions when the practical data is used in training the artificial neural network model.