Research on Non-Inferior Nash Equilibrium in Power Spot Market

Nash equilibrium is an important decision-making result for all players in non-cooperation game. In existed Nash equilibrium model, the cooperation relationship between the generation groups is not taken into account. Thus, in this paper, the non-inferior Nash equilibrium model of power spot market considering the power network constraints is proposed, in order to effectively describe the characteristics that both cooperation within each generation group and competition between the groups coexist. This model is a bi-level optimization model, in which the upper layer is the profit optimization model of generation group, and the lower layer is the market clearing optimization model considering the power network constraints. By using the nonlinear complementarity function to reformulate the KKT system for the optimization problem, the non-inferior Nash equilibrium of power spot market is solved simply and fast. Corresponding to different operational conditions of power network, i.e., congestion and non-congestion, the non-inferior Nash equilibrium of power spot market is analyzed and compared with different market parameters. The results indicate that the generation groups´ production strategies are favorable to the power plant locating at the important place of power network when congestion occurs.