Challenges and benefits in developing and applying FACTS technology in the USA

Summary form only as given. As the US electric utility industry undergoes its most fundamental transition in a century, many forces of change are converging on power delivery systems. In the United States, deregulation at both the state and federal levels is increasing competition among utilities and bringing new participants into the electricity market. The most pressing needs for the electric utility industry are how to increase the capability, controllability and flexibility of power transfer of existing transmission facilities while maintaining the reliability of the power delivery. The flexible AC transmission system (FACTS) is a technology-based solution envisioned by EPRI to help the utility industry deal with changes in the power delivery business. A major thrust of FACTS technology is the development of power electronic-based systems that provide dynamic control of the power transfer parameters of transmission voltage, line impedance and phase angle. In other words, the transmission system becomes an active power delivery element, playing an active role in determining real and reactive power flow and in containing power transfer dynamics. The results are, therefore, better utilization of transmission assets and increased flexibility, reliability, and security of power delivery. This paper presents the challenges and the proven technical and economical benefits of FACTS Controllers developed and under development by EPRI and power utilities in the USA.