Research On Optimal Bidding Strategy For Combined Cycle Unit In Day-ahead Energy And Reserve Markets

With the continuous development of natural gas combined cycle power generation technology,the installed capacity of the combined cycle unit is gradually increasing due to its flexible operation characteristics.The rapid development of the combined cycle unit fueled by clean and environmentally friendly natural gas is conducive to promoting the clean and low-carbon development of the power system,so as to achieve double carbon goals.The combined cycle unit participates in the day-ahead energy and reserve markets.Due to its flexible mode transfer,it can not only provide energy and flexible reserve resource for the system but also improve the profit of the combined cycle unit in the electricity market.Therefore,developing an effective bidding strategy for the combined cycle unit in day-ahead energy and reserve markets is necessary.The combined cycle unit can adjust the operation mode by developing the bidding strategy in the energy and reserve market,so as to reduce the cost of the unit generated by the consumption of natural gas power generation,reduce the cost of providing energy and reserve to the system,and at the same time realize the improvement of the profit of the combined cycle unit in the electricity market.Based on the above research background,the main research work of this paper is as follows:(1)This paper describes the structural characteristics and operation principle of the combined cycle unit,expounds on the advantages of the combined cycle unit,analyzes the mode transfer characteristics of the combined cycle unit,and establishes the mathematical model of the mode-based combined cycle unit.(2)In order to study the bidding behavior of the combined cycle unit in the day-ahead energy market,a bi-level model of bidding strategy for the combined cycle unit in the energy market is proposed in this paper.The upper-level model is the bidding model for the mode-based combined cycle unit,and the lower-level model is the day-ahead energy market clearing model.In this model,the combined cycle unit and the independent system operator(ISO)influence each other by the locational marginal prices(LMP)obtained from the lower-level market-clearing model.By using the Karush-Kuhn-Tucker(KKT)condition and duality theory,the proposed bilevel optimization model is transformed into a mathematical program with an equilibrium constraint(MPEC)problem.Through the analysis of the results of the example,the effectiveness of the proposed bidding strategy to improve the profit of the combined cycle unit in the market is verified.(3)Considering the influence of the joint clearing of the day-ahead energy and reserve market on the bidding behavior of the combined cycle unit in the market,a bi-level optimal bidding strategy model for the combined-cycle unit in joint day-ahead energy and reserve markets is proposed.The upper-level model is an optimal bidding model for the mode-based combined cycle unit,whose goal is to maximize its profits.The lower-level model is the joint market clearing model of the energy and reserve markets managed by the ISO.The combined cycle unit and ISO in this model influence each other by the locational marginal electricity prices(LMEP)and the locational marginal reserve prices(LMRP)obtained from the lower-level market-clearing model.The combined cycle unit submits the bids to ISO and arranges the generation plan according to the market-clearing results of the lower-level market-clearing model carried out by the ISO.By using the KKT condition and duality theory,the proposed bi-level optimization model can be transformed into the MPEC problem.The validity of the proposed bidding strategy for the combined cycle unit is verified by an example analysis.The results show that the proposed bidding strategy can effectively improve the profit of the combined cycle unit in the energy and reserve market.