Estimation of overhead conductor temperature using artificial neural networks
University of Maribor, Faculty of Electrical Engineering and
University of Maribor, Faculty of Electrical Engineering and Computer Science
Dynamic thermal ratings of overhead lines could represent a promising approach to increase the transmission capacity by considering a weather dependent thermal ratings of overhead power lines in real time instead of using constant ratings. Knowledge about aforementioned is not only needed in real time observation but as well in a day-ahead basis within a network operational planning and in order to assess network security .
The key elements in the development of a dynamic-line rating system are the conductor type, ambient temperature, solar radiation and wind speed with its direction in a real time . Joule and magnetic heating refer to the conductor heating due to its resistance and due to cyclic magnetic flux which causes heating by eddy currents, hysteresis and magnetic viscosity (magnetic heating) , while for precise evaluation of solar heating, numerous parameters are relevant, e.g. the conductor’s inclination to the horizontal or the intensity of the direct as well as diffuse solar radiation . On the cooling side the forced and the natural convective cooling (wind speed and its direction) are important, while further heat losses occur by a thermal radiation, depending on conductor surface temperature .
This paper aimed to use the artificial neural network to estimate the conductor temperature of an overhead power line. Using both, the measured and calculated data, the accuracy of the artificial neural network will be evaluated. In that manner, to train the artificial neural network, ambient temperature, solar radiation and wind speed values are an inputs, and the conductor temperature is an output. So, the artificial neural network is used to estimate the conductor temperature, while the feed forward artificial neural network will be trained by using a different algorithms. The input learning signal (pattern) of the artificial neural network in the learning process is the value of the aforementioned variables. According to the conductor temperature, the output learning signal of the presented solution (target) will be set to the value zero or one.
In the paper will be shown that application of artificial neural network, as part of aforementioned problem, could represent a promising solution.
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