Calculation of thermal field and ampacity of overhead power transmission lines using finite element method

The population explosion and development of the national economy are two main causes of increasing the power demand. Besides, the Distributed Generations (DG) connected with the power transmission and distribution networks increase the transmission power on the existing lines as well. In general, for solving this problem, power utilities have to install some new power transmission and distribution lines. However, in some cases, the install of new power lines can strongly effect to the environment and even the economic efficiency is low. Nowadays, the problem considered by scientists, researchers and engineers is how to use efficiently the existing power transmission and distribution lines through calculating and monitoring their current carrying capacity at higher operation temperature, and thus the optimal use of these existing lines will bring higher efficiency to power companies. Generally, the current carrying capacity of power lines is computed based on the calculation of their thermal fields illustrated in IEEE [1], IEC [2] and CIGRE [3]. In this paper, we present the new approach that is the application of the finite element method based on Comsol Multiphysics software for modeling thermal fields of overhead power transmission lines. In particular, we investigate the influence of environmental conditions, such as wind velocity, wind direction, temperature and radiation coefficient on the typical line of ACSR. The comparisons between our numerical solutions and those obtained from IEEE have been shown the high accuracy and applicability of finite element method to compute thermal fields of overhead power transmission lines.