# Evolutionary Game Analysis of Power Generation Groups Considering Energy Price Fluctuation
### Research Background  
Coal-fired power plants use thermal coal as the primary energy for power generation, and coal prices have a huge impact on their power generation costs and objectively become a coal-fired power generation group. Similarly, gas-fired power plants use natural gas as primary energy and objectively form a gas-fired power generation group. Among the market analysis methods based on game theory, the commonly used mathematical methods included the supply function equilibrium model [7], the Stackelberg model [8], and the Conjectural Variation model [9]. The above models cannot consider the long-term impact of the energy price-generation cost transmission mechanism on the group bidding strategy of power generators, so they are not suitable for studying the group behavior of many power generators in complex market environments such as primary energy price fluctuations. Evolutionary game is suitable for studying group game behavior in the market. Its theory originates from the long-term interaction of competitive behaviors in the process of biological evolution [10]. The biggest feature of the evolutionary game is that the strategy that produces higher expected returns is used as the direction of the optimal strategy [11; 12]. In addition, it has a good prospect in the group behavior characteristics of a long period and a large spatial span. The theory of group evolution strategy usually emphasizes the gradual optimization of the subject's strategy under the influence of direct macro factors, and the influence of various factors on the evolution in a complex environment can be reflected in the payment matrix of the power generation group [13]. Therefore, the evolution process of the bidding behavior on the power generation side can be comprehensively and accurately analyzed when the energy price fluctuates. Under the background of limited rationality and information asymmetry of market participants, evolutionary game theory has been widely used in the study of market players' behavioral decision-making problems in recent years. Based on the complexity of the real market environment, many studies tend to use multiple game models to simulate the behavior of market participants. For example, [PERSON] et al. proposed a hierarchical game approach for enabling reliability-differentiated services in a residential distribution network with plug-in hybrid electric vehicles. At the upper level of the hierarchical game, an evolutionary game is formulated to optimize the management of the vehicle-to-grid capacity of each vehicle. Ref. [14] [PERSON] at al. Proposed a novel game-theoretic model for peer-to-peer (P2P) energy trading among the prosumers in a community, in which evolutionary game theory is used to model the dynamics of the buyers for selecting sellers. Ref. [15] [PERSON] et al. studied the demand response problem of multiple utilities and multiple residential users based on evolutionary games and non-cooperative games, and the results show that the proposed scheme can significantly reduce peak loads. Ref. [16] In addition, the evolutionary game has been involved in power generation bidding [17], energy system supervision [18; 19], microgrid energy management [20], and other fields. The above references do not consider the long-term dynamic interaction behavior of various types of power generators under the background of primary energy price fluctuations. By considering the impact of primary energy price fluctuations on power generation costs, this paper proposes an evolutionary trend analysis of bidding for coal-fired and gas-fired power generation groups based on evolutionary games and establishes a power generation side game model under the influence of multiple factors. Under the background of primary energy fluctuation, the equilibrium state of the power generation side game under different supply-demand relations and the conditions that the equilibrium state needs to meet are proposed.