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 th e Inez Substation of American Electric Power (AEP) in eastern Kentucky. The project is a collaborative effort between AEP, the Westinghouse Electric C orporation, and the Electric Power Research Institute (EPRI). Comprising tw o +/-160 MVA voltage-sourced GTO-thyristor-based inverters, this installati on is the first large-scale practical demonstration of the UPFC concept, an d its completion is a significant milestone in the progress of power electr onics technology for Flexible AC Transmission System (FACTS). This paper briefly reviews the main features of the Inez installation and d iscusses the operation of the equipment. A collection of measured performan ce characteristics is presented to illustrate the unique capabilities of th e 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 reg ulating the local bus voltage. The results include a demonstration of the s eries inverter at Inez, operating in stand-alone mode. This test constitute s the first practical large-scale demonstration of the Static Synchronous S eries Compensator (SSSC) concept.