Research On Bidding Problems For Hydropower Plant In Electricity Market

Along with electricity market reform advancement in China, the hydropower plants will gradually head for the market gradually and become competitive utility. Because of its characteristics, there must be a lot difference from the thermal power plants in consideration of participating in market competition for the hydropower plants. In the electricity market, the hydropower plants need to coordinate water usage during the periods of scheduling and eventually transform the information into the bidding strategy, thereby maximizing their economic benefit.Up to now, there are a lot of researches on the electricity market. However, the theoretical and practical validation of the researches was primarily based on thermal systems, and cannot be simply extrapolated to hydrothermal systems. Based on the analysis of present situation with regard to the theoretical research on electricity market, this paper is to develop some methodologies and tools centered on primary issues of bidding strategy and strategic bidding for hydropower plant, and conclude some valuable theoretical results.First of all, in consideration of its own characteristic the maximal benefit realization problem is carried out for hydropower plant's piecewise bidding with several bid price/quantity bands when participating in day-ahead market. Then The bidding models for constant water head and variable head hydropower plant are established and augmented matrix is developed, then the coupling coefficient of water balance equation is also mathematical analyzed, which provides a theoretical means of analyzing relation between bidding price and released water and builds an optimal relationship between the bidding quantity and price, to solve the piecewise bidding problem based on self-scheduling implicitly tackling the price uncertainty. The case of unavailable incremental water consumed is also discussed. Therefore, a complete solution for hydropower plant is presented, which has shown better performance of satisfying the hydropower plant water restrictions and ensuring the realization of profit maximization compared with the single bidding. Secondly, strategic bidding issues of hydropower plant as price-maker "rational" is studied. And Cournot model is used for solving one-stage equilibrium problem. Equilibrium migration and credibility threat is also discussed. Thereby the strategic bidding solution for the entire period considering temporal correlation is obtained to provide decision support for hydropower plant. Evolutionary game theory is introduced to study the Equilibrium problem for the long-term bidding process, trying to analysis the generation companies bidding behavior from dynamic perspective.Finally, combined with the physical contract and the finance contract, bidding models for piecewise bidding strategy and strategic bidding are established. Considering the contract, generation scheduling must be arranged to maximize benefit according to the relevant transaction scheduling and the status of bidding units on the premise of contract quantity decomposed. The different realization approaches are used to realize the optimal problem of different contracts and different bidding methods. Based on theoretical analysis of optimization condition, the piecewise bidding solution is got. Relaxing the contract quantity restraint to get the initial optimal solution and adjust to the satisfied solution. Influence of different contract on different bidding manner is discussed at last.At the end of paper, the possible problems and directions for further research are pointed out.