Economic Valuation and Optimal Deployment of Static Synchronous Series Compensators for U.S. Power System Expansion

TL;DR

This paper models the U.S. power system's expansion to 2050, demonstrating that widespread deployment of Static Synchronous Series Compensators (SSSC) can significantly reduce costs and transmission reinforcement needs.

Contribution

It introduces a capacity expansion model incorporating SSSC effects, showing their cost benefits and strategic deployment advantages in large-scale power system planning.

Findings

SSSC deployment reduces annual system costs by $1.9 billion.

SSSC deployment decreases transmission reinforcement needs by 20%.

Benefit-cost ratios of 59 are achieved in the Midwest for SSSC deployment.

Abstract

Flexible AC Transmission Systems (FACTS), particularly Static Synchronous Series Compensators (SSSC), can improve network transfer capability and complement restricted transmission expansion. Evaluations of FACTS within large-scale, real-world power system planning are currently lacking. This paper develops a capacity expansion model for the contiguous U.S. power system toward 2050, incorporating SSSC-modified linear power flow equations and accounting for impedance feedback in transmission expansion. Cost-optimal system expansion leverages widespread nationwide SSSC deployment on small-to-medium capacity lines and reduces the number of corridors to be reinforced. Overall, SSSCs reduce annualized system costs by $1.9 billion or decrease transmission expansion requirements by 20%. The most advantageous deployments achieving benefit-cost ratios of 59 concentrated in the Midwest, facilitating the delivery of central U.S. wind power to eastern load centers. The value proposition of SSSCs is robust to cost sensitivities and potential competition from HVDC network expansion, and increases under higher demand growth and more stringent decarbonization policies. These findings provide a blueprint for leveraging SSSC deployment in the U.S. power system.