ABSTRACT
Increase in the power demand requires the development of EHV AC double circuit and high power carrying capacity lines. Generally, the power generating stations are far away from the distribution network and to connect the power surplus region to power deficit region we need long EHV AC double circuit transmission lines to carry large amount of power. But the long EHV AC transmission lines are limited by their SIL (Surge Impedance Loading) limit which is much below the thermal limit of conductor due to large inductive reactance of the line. SIL depends on various factors and geometrical arrangement of double circuit transmission lines i.e. bundle spacing, diameter of conductor, no. of sub-conductors per phase, etc. In this paper an attempt is made to present various techniques implemented on EHV AC double circuit transmission lines to improve SIL level and also its effect on corona loss is shown with the help of mathematical programming in Matlab software. In this paper various double circuit configuration and its comparison is also presented.
