Study On Power Market Short-term Optimization Problems

In this dissertation, the development of worldwide power market has been reviewed and the research and application topics of short-term optimization operation in power market have been summarized. Several key power market short-term optimization problems, such as unit commitment, auction problems in pool-based power market, power transaction and node price calculation and transfer capacity calculation are comprehensively and thoroughly studied and analyzed in this dissertation. The main contents and contributions are as follows:(1)Unit Commitment (UC)based on the generic algorithm (GA) with different implementation techniques, such as different sampling space, different selection schemes, different fitness scaling methods and different crossover/mutation rate, is developed and implemented in 10 unit system and 110 unit system. This paper thoroughly studies the effects on convergence time, number of generations and convergence value of GA due to different implementation techniques, which indicates that the algorithm is effective in a certain degree, and reveals that different implementation techniques have great effect on convergence time, number of generations, and convergence value of GA-based UC. A good foundation is laid for further practicable study of GA-based UC. (2)The auction problem in power pool is presented. It employs dynamic programming to deal with single unit optimization and adopts a joint method of LR (Lagrangian Relaxation), sub-optimal treatment and economic operation to calculate market equilibrium. The algorithm can avoid unsteadiness of LR results and give market equilibrium in sub-optimal level. The proposed method has been tested on 10-unit system and 110-unit system. The calculation process demonstrates that the algorithm reliably converges to a good result. The result shows the feasibility and practicality of this approach. (3)The DC-OPF and AC-OPF based mathematical model for power transaction are established respectively. The formula for calculating node price and its individual components is proposed. The characteristics of node price are analyzed and the revenues gained by market participants are also calculated. The node price calculated through DC-OPF can reveal transmission congestion. The node price calculated through AC-OPF contains all components, and the active node price and reactive node price affects with each other. Simulation calculation validates the formula of calculating node price and its components.(4)The calculation of Available Transfer Capability (ATC) has become an important part of the research on the power market, while the calculation of Total Transfer Capability (TTC) is the foundation of ATC. This paper introduces the essential conception and calculating rules of ATC. The OPF-based TTC calculation model is established, in which six differentobject functions are presented. A theorem gives the proof of the equivalence of the six object functions used to calculate TTC under specific conditions. This paper testifies the feasibility of OPF-based TTC calculation by IEE-30 bus system and proves the validity of the theorem through practical examples.