| Description |
Congestion exists commonly in electric power transmission systems, and it can significantly increase generation dispatch costs and negatively affect renewable energy integration. Each year, the generation dispatch cost increase induced by transmission congestion is $3-4 billion in the U.S., and transmission constraints are leading causes of renewable energy curtailment. One way to mitigate transmission congestion is through transmission expansions. However, transmission expansions are not only expensive but also take up to 10 years to go through the approval and construction processes. Thus, there is a need to make better use of the existing transmission system to mitigate congestion. One way to make better use of the existing transmission network is through using power flow control technologies. Transmission-level power flow control technologies mainly include transmission switching (TS), flexible AC transmission systems (FACTS), and the emerging distributed FACTS (D-FACTS). This research aims to find computationally tractable ways to allocate and configure power control technologies optimally, compare different power flow control technologies, study their interdependence, and reveal the benefits of power flow control technologies in terms of reducing generation dispatch cost and renewable energy curtailment. In this research, optimal allocation and configuration models for power flow control technologies were developed, and case studies were carried out on a modified IEEE 118- bus test system and modified RTS-96 test systems. A few key findings are summarized from the simulation results: (1) using power flow control technologies properly can significantly reduce generation dispatch cost and renewable energy curtailment in a system; (2) with the same level of investment, D-FACTS can result in more savings in generation dispatch cost than conventional FACTS due to its low cost and flexibility in redeployment; (3) co-optimizing TS and FACTS can result in more savings in generation dispatch cost than using either technology exclusively; (4) co-optimizing TS and energy storage (ES) is necessary in power system operations when both technologies are used. |
