Automated transmission expansion and routing incorporating electric and geographic criteria

Transmission has seen renewed investment in the U.S. over the past decade, as the nation seeks to modernize its aging power infrastructure. While the technical side of transmission planning seeks improvements to the grid to enhance reliability and/or economy of operation, transmission line siting (TLS) must include the very challenging process of routing transmission corridors to respect geographic and land-use constraints. Among other factors, acquisition of rights-of-way, compliance with state and federal agencies, and environmental impact of transmission lines are all investigated in transmission line siting. While strides have been made to improve the process in the past decade, transmission line siting remains a controversial and difficult process. Transmission line siting in a post-restructuring electric industry will be covered in this paper. We review the important role played by non-electric constraints such as geographic barriers, regulatory impact, public/stakeholder input, etc. in transmission expansion planning. We introduce an approach that provides a first step towards an automated, optimization-based approach incorporating geographic decision factors, and most critically, line length. This modification to the authors' previous transmission expansion work allows weighing of system-wide electrical performance contributions of a transmission line in conjunction with geographic impact.