Bakhtiar Zohouri Zanganeh - Tehran Regional Electrical Company
Hossein Ali Mohammadpour - Electrical Department of Iran University of Science and Technology
Reza Ghandehari - Tehran Regional Electrical Company
Davod Habibinia - Electrical Department of Hashtrood Azad University

Conductor temperature is one of the important parameters which limits energy transmission in electrical systems. By identifying of transmission system, transmission lines and its critical points and also climate condition of the region where the system is placed, conductor’s real temperature can be calculated. Having these information causesto increase capacity and to use the transmission lines capacity effectively, without loosing of transmission network safety. In this article, allowable confines of transmission lines capacity are determined, and maximum transmittable line powers are calculated, respect to lines conductors temperature. Then different methods to determine transmission lines ampacity, respect to climate condition are represented. These methods are compared in an economical load flow. At the end, it is concluded that selection of proper method to estimate transmission line ampacity, results economical providence, without violation of line temperature from allowed boundaries.

Transmission Line, optimum operation, climate condition, ampacity