Expansion of transmission systems in a deregulated environment

Transmission congestion is an unavoidable consequence of power industry deregulation. Congestion can be relieved through either generation rescheduling or transmission system expansion, both resulting in increased operating cost. An optimal generation rescheduling approach, which is based on an AC method, is introduced. The proposed method can be utilized to optimize a generation re-dispatch scheme in case of transmission congestion. Expansion of the transmission system needs to be considered if the cost of generation re-dispatch is greater than the investment cost of expansion. An analysis to determine a transmission expansion scheme is also presented.