Research On Power Economy Of District Energy System Considering Wind-photovoltaic-thermal Coupling

Under the background of the intensification of the global greenhouse effect,the accelerated depletion of fossil energy and the green and low-carbon transformation of national energy,the integration of a high proportion of renewable energy into the grid is an important way for China to achieve the "dual carbon" goal and promote energy transformation.However,as the national energy authorities have gradually completed subsidies for newly approved wind power and photovoltaic power generation projects,the income of wind power and photovoltaic power generation projects in the district energy system has been seriously affected.In northern China,the construction of a regional energy system coupled with wind-photovoltaic-thermal can become an effective way to solve existing market problems with excellent cost and output characteristics.This paper summarizes the research status of the existing evaluation methods of regional energy system investment benefits of wind power and photovoltaic access,as well as the joint operation of renewable energy and flexible resources,and puts forward the main research ideas of this paper in view of the limitations of the existing research results,and achieves the following research results:Firstly,considering the whole life cycle cost and revenue composition of wind power and photovoltaic power generation projects,a mathematical model for optimizing investment benefit evaluation indicators taking into account multiple influencing factors was constructed.In addition,project examples in northern China were selected to analyze the sensitivity of multiple sensitivity indicators under multiple subsidy "slope decline" scenarios and the average transaction price of carbon trading.Secondly,under the premise of meeting certain requirements for return on investment,the impact of changes in unit investment costs on the feasibility of grid parity is further discussed from the perspectives of considering and not considering carbon reduction benefits for new wind power and photovoltaic power generation projects in northern China.The feasibility analysis results of grid parity are compared with China’s electricity price policy,which verifies the rationality and practicality of the investment benefit evaluation method of power generation projects proposed in this paper.Then,based on the current situation of annual bilateral transactions of renewable energy and thermal power in northern China,the research value of building a wind-photovoltaic-thermal coupled system to participate in the annual bilateral trading market as an independent operator under the same grid connection point is analyzed.Considering the influence of renewable energy output on the revenue of wind-photovoltaic-thermal coupled system,based on the real data analysis of project examples in northern China,the output characteristics of wind power and photovoltaic are proposed,and a clustering algorithm combining ordered clustering and optimized k-means clustering algorithm suitable for renewable energy annual output clustering is proposed,and the typical scenario set of renewable energy annual output generated can effectively provide data support for the income calculation of wind-photovoltaic-thermal coupled system.In addition,the game relationship between market parties in annual bilateral transactions is clarified,and the annual bilateral transaction market objective function between power generation enterprises and large users is constructed.Finally,based on the above research content,the annual master-slave game model of windphotovoltaic-thermal coupled system considering the competition of multiple power generation enterprises is constructed,the solution method and steps of the model are given,and the windphotovoltaic-thermal bundling is set as the market revenue reference group,and the market revenue of wind-photovoltaic-thermal coupled system and wind-solar thermal bundling is analyzed and compared through simulation.The analysis shows that the construction of a windphotovoltaic-thermal coupling regional energy system can not only improve the level of complementarity and mutual assistance of grid-connected resources,maximize the benefits of the annual bilateral trading market,but also effectively solve the practical problems faced by renewable energy and thermal power in the current annual bilateral trading market.