AEP unified power flow controller performance

The installation of the world´s first unified power flow controller (UPFC) has been completed and a series of commissioning tests were conducted at the Inez Substation of American Electric Power (AEP) in eastern Kentucky. The project is a collaborative effort between AEP, the Westinghouse Electric Corporation, and the Electric Power Research Institute (EPRI). Comprising two ±160 MVA voltage-sourced GTO-thyristor-based inverters, this installation is the first large-scale practical demonstration of the UPFC concept, and its completion is a significant milestone in the progress of power electronics technology for flexible AC transmission system (FACTS). This paper briefly reviews the main features of the Inez installation and discusses the operation of the equipment. A collection of measured performance characteristics is presented to illustrate the unique capabilities of the UPFC. These dynamic measurements were made in the course of commissioning, and they graphically illustrate the ability of the UPFC to independently control the real and reactive power on a transmission line, while also regulating the local bus voltage. The results include a demonstration of the series inverter at Inez, operating in stand-alone mode. This test constitutes the first practical large-scale demonstration of the static synchronous series compensator (SSSC) concept