This master thesis aims to investigate whether an installation of a High Temperature Low Sag-conductor (HTLS-conductor) could be beneficial for a 130 kV-transmission line owned by the Swedish company Vattenfall. The HTLS-conductors investigated in this thesis were ACCC-conductors and three different models were included: Warsaw, Dublin and Stockholm 3L ACCC-conductors. The aim of an installation was to roughly double the thermal line rating without needing to replace any supporting towers in the line section that was studied.    Simulations were conducted using MATLAB and PLS-CADD Ultralite and included calculations of the thermal line rating as well as conductor sag and tension in the supporting towers. The results showed that all three ACCC-conductors fulfilled Vattenfall’s requirements for increased thermal line rating. However, conductor sag was a problem which required an increase in tension. This increase in tension was only possible for Warsaw and Stockholm 3L ACCC-conductors. The Dublin ACCC-conductor proved too heavy and would have required a replacement of supporting towers if installed in this line section.    Finally, the thesis recommends further studies of the effects of an installation of Warsaw and Stockholm 3L ACCC-conductors and also suggests investigations concerning economic profitability, environmental sustainability and suitability of other types of HTLS-conductors.