In 1995, American Electric Power (AEP), an investor owned electric uti
lity company, completed detailed planning studies to resolve voltage a
nd thermal loading concerns in parts of its Kentucky/West Virginia ser
vice areas. These studies led to the initiation of a project including
a Unified Power Flow Controller (UPFC), which is currently being deve
loped through a tailored collaboration by AEP, Electric Power Research
Institute (EPRI), and Westinghouse Electric Corporation (Westinghouse
). This paper describes the planning concerns, the study objectives, a
nd the UPFC function in resolving these concerns. It also provides inf
ormation on the UPFC modeling for system studies and its technical par
ameters that would be of interest to transmission system planners and
other prospective users of this new technology.