Technical challenges of computing available transfer capability (ATC) in electric power systems

A key concept in the restructuring of the electric power industry is the ability to accurately and rapidly quantify the capabilities of the transmission system. Transmission transfer capability is limited by a number of different mechanisms, including thermal, voltage, and stability constraints. This paper discusses the ATC definitions and determination guidelines approved by the North American Electric Reliability Council (NERC) and presents several concepts for dealing with the technical challenges of computation.