| This dissertation presents a novel methodology to coordinate path transfers across multiple control areas without compromising system security and stability in large interconnected power system. Trajectory based analysis method on the model of the western blackout event on August 10, 1996 is carried out for studying the impact of unstable limit cycles on the evolution of the disturbance.; The maximum power that can be transferred over any transmission line, called the transfer capability, is limited by constraints on thermal limits, voltage bounds, and security considerations. As the power system gets more stressed with increasing loads, the need to transfer power over long transmission lines is becoming very important. This is especially the case for deregulated markets where it is attractive to minimize costs by buying power from remote generators with lower generation costs.; In the present power system operation, the transfer capacity studies of transmission lines are carried out separately by their owners with little coordination. The objective of this dissertation has been to propose a global framework for coordinating the capabilities of several transmission paths, while also meeting the regulatory requirements on voltage security and dynamic security. As an example, we focus on maximizing the transmission capacity of the California-Oregon AC Inter-tie, by coordinating other path-flows that have an impact on the COI capacity. We show that substantial improvements in the COI MW transfer can be achieved with reasonable rescheduling of neighboring tie-line flows or area generations using the optimization algorithms presented.; These coordination algorithms would be of vital importance in stressed power-flow scenarios when there is a need to increase the capability of one or more critical transmission lines by rescheduling of other paths, while also satisfying strict requirements on system security.; A novel method is proposed for locating unstable limit cycles in large-scale power system models. The algorithm is illustrated for the study of unstable limit cycles in a validated model of the August 10, 1996 WSCC western power system blackout. |
