Diversifying Transmission Planning of Wind-Heavy Systems by Incorporating Dynamic Line Rating

Expanding electric transmission capacity for renewable energy sources such as wind and solar is essential for decarbonization efforts and meeting increased load demand. This typically requires significant investments in new transmission lines or upgrades to existing ones. However, enhancing the efficiency of current infrastructure can also be highly beneficial. Recently, the use of Dynamic Line Ratings (DLR) has gained significant attention from utilities. DLR allows operators to use lines at their true capacities by considering weather conditions, which can be much higher than the conservative static line ratings. This paper presents a methodology for identifying and implementing DLR on selected lines to enhance capacity and reduce upgrade costs. Line identification is performed using power flow tracing algorithms, where lines carrying more wind power are chosen as candidates for DLR implementation. A criticality score, which is a function of the average wind power flow in the line and the worst-case loading level, is then defined to prioritize the lines that need DLR implementation. The proposed method is tested on a modified system based on the Western Kansas area, with estimated cost savings evaluated. The criticality of these transmission lines during $(n-1)$ contingencies is also evaluated. Additionally, alternative reinvestment strategies for these savings are explored, which show their potential benefits for system security and reliability.