Study On Transmission Adequacy Based On Optimal Power Flow In Electricity Market

Transmission capacity plays a significant role in realizing fair competition and controlling operation stability in both power system and electricity market. How to accurately assess the adequacy of transmission and how to maximize the demands of all parties from electricity market are the key topics concerned by organizers and participants in electricity market.This thesis based on the crucial lines in power system as research object, studies the effect of stability limit of transmission line on transmission adequacy from security and reliability of system operation by means of AC-OPF. The deduction is that the product of stability limit factors and shadow price on some line could reflect the economic value, by which the stability limit interval in system operation is also well estimated from both secure and economic viewpoints. In addition, OPF problem with expected security cost is discussed. Furthermore, with all market clearing results based on DC-OPF, the relationship among system purchase cost, shadow price on line, as well as stability limit of transmission line is discussed under the assumption that system congestion situation is given. At last this thesis puts forward multi-level market power index based on must-run generation. Numerical simulating result shows that this method could reveal the weakness and critical operation point in transmission network.The result of this thesis could not only help to furnish the market rules and but also provide reasonable evidence for transmission planning of expanding electricity network.