基于智能电网技术的能源网络供应链买电策略研究

Optimal Energy Procurement Policies in Smart Grid Energy Supply Chain Networks

智能电网的提出不仅是电网技术本身发展的需要,更是各国能源和经济发展战略层面的需要。可再生能源作为清洁能源的突出代表,其分布式发电系统是智能电网发展的必然趋势。但是,由于天气等因素导致的可再生能源高度不确定性和间歇性却给智能电网系统的稳定带来很大挑战。为了应对这一挑战,并发挥可再生能源的成本优势,本文从微观运营的角度,研究带有可再生能源供给的"多对多"能源网络供应链的买电决策问题,求得能源集成商的最优买电量,以及能源短缺成本、发电厂产能、可再生能源不确定性等参数对最优解的影响。本文发现,发电厂产能对能源集成商使用可再生能源的策略有直接影响。并且,可再生能源产能较大的能源集成商因为规避不确定性风险反而会提高买电量。本文的结论能帮助智能电网节省用电成本,为实现节约型、可靠型和稳定型电网系统提供一定参考。

The smart grid is not only the need of the development of grid technology itself,but also shines the light on the road of the economic and energy development for various countries.As a prominent representative of clean energy,the distributed generation system of renewable energy is the inevitable trend of smart grid development.However,the high uncertainty and intermittence of renewable energy due to weather and other uncertain factors pose great challenges to the stability of smart grid systems.In order to meet this challenge and give full play to the cost advantage of renewable energy,the decision-making problem of energy procurement in the many-to-many energy network supply chain with renewable energy supply is studied from the perspective of micro-operation,so as to obtain the optimal energy procurement amount for energy integrators,as well as the impacts of the energy shortage cost,power plant capacity and renewable energy on the optimal solution.An energy supply chain network composed of distributed micro-grid is considered.The energy supply chain network consists of multiple power plants and smart grids.Each smart grid is equipped with renewable energy,such as wind turbines or solar panels.In the smart grid,energy integrators are responsible for collecting users’demands and deciding to purchase the total power of traditional energy from power plants.If the uncertainty of renewable energy output leads to the imbalance of energy supply and demand,it is necessary for integrators to temporarily meet the demand of surplus power through the auxiliary power market,but occurring very high penalty cost.With the goal of minimizing the total cost,the integrator makes the optimal electricity purchase decision based on the power plant price and capacity,user demand and the prediction of renewable energy distribution.Game theory in the proposed supply chain network is used.The decision process is as follows.First,the power plants decide the electricity prices.Second,the integrators decide procurement quantities from each power plants.Third,the renewable energy output is realized.Finally,the integrators use purchased traditional power and renewable energy to satisfy smart grid users’demand,penalty cost occurs if there are any unsatisfied demands.Two research circumstances are considered.The first one is when the renewable energy can be perfectly controlled.The second one is when the renewable energy cannot be controlled,but only can be predicted based on its distribution function.It is found that the power generation capacity of the power plant has a direct impact on the strategy of energy integrators to use renewable energy.Moreover,energy integrators with larger renewable energy production capacity will increase their energy procurement amount even more to avoid the risk of uncertainty.Numerical studies are conducted to show our results.In the perfect case,the distribution proportion of the power plants’capacity is only related to the penalty cost.It can be seen that if the smart grid is located in a remote area or has other factors that cause large energy waste,the penalty cost will be larger,and the larger the distribution proportion,that is,the higher the priority of energy access.However,in the uncertainty case,it is found that if integrators further invest in renewable energy capacity and improve the ability of energy self-sufficiency,the proportion of traditional energy from power plants should be reduced.However,the opposite conclusion is found.When the integrator’s own renewable energy capacity increases,it will increase the traditional energy proportion from the power plants.The conclusions of this paper can help smart grid energy integrators to save electricity costs,and provide some reference for realizing economical,reliable and stable power grid system.