Transmission Expansion Planning (TEP)-Based Unconventional High Surge Impedance Loading (HSIL) Line Design Concept

This paper develops a new concept that we call transmission expansion planning (TEP)-based unconventional high surge impedance loading (HSIL) line design. To date, these two areas (TEP and transmission line design) have been conducted separately. For TEP, planners typically use the electrical parameters of a few standard conventional line designs to study planning scenarios, and then, the final candidate line is constructed. In such a sequence, cost-effective scenarios often do not meet the technical criteria of load flow. In this paper, we will study whether this sequence can be overturned; namely, can a transmission expansion planner get optimal line parameter values that lead to the most cost-effective scenario, and then have a transmission line with those parameters be designed? Although this cannot currently be realized through conventional designs, in this paper, we demonstrate that it is a possibility if breakthrough designs for transmission lines are used by shifting phase configurations and subconductors into unconventional HSIL arrangements, leading to the optimal line parameters determined by TEP.