Studies On Unit Commitment In Electricity Market

Electricity transaction is the kernel problem of electricity market. Due to particularity of electricity and specialty of power industry, Unit Commitment (UC) is turned into an important kind of trading mode in the managed day-ahead electricity market. The thesis focuses on unit commitment problem in electricity market, aims at revealing function and questions of unit commitment in competitive power market, and searching for solution methods. The thesis means a lot of theoretical and practical sense to electricity transaction study.Up to date, there are still some problems which are in urgent need of research about unit commitment, such as integrating electrical power technology with market principle, uncovering restriction mechanism of transmission network to electricity transaction, introducing demand response to improve the wholesale one-side market. Centering discussion on unit commitment problem in competitive market, the thesis does such innovative works as follows:First, based on knowledge of technical improvement of electrical power industry and changes of its running environment, a comprehensive mathematical model is established. In the Pool mode, electricity transaction is undoubtedly a unit commitment problem. The most efficient and promising solving method of the problem is Lagrangian Relaxation (LR) method. Discussion shows, unit commitment in electricity market is more complicated than traditional unit commitment problem. The difficulty lies on handling of discrete variables and introduction of market rules. A geometrical analysis intuitively reveals the causation, at the same time inevitability of duality gap is also proved. The philosophy on which unit commitment auction bases to determine the market equilibrium leads to the conclusion that unit commitment is a necessary and rational tool for particular kind of electricity market. The conclusion is useful to understand the running mechanism of an imperfect competitive market.Second, the thesis studies fairness problem caused by identical or similar units in unit commitment. The problem is an embodiment of the effect that electrical power technology...