Bidding Strategy And Coordinated Dispatch Of Virtual Power Plant With Multiple Distributed Energy Resources

In face of global energy crisis brought by fossil energy depletion,the progress of renewable energy generation technology has become an essential support for worldwide sustainable development.Along with the rapid improvement in renewable energy technology,more and more distributed renewable energy resources are deployed in user-side.Although the deployment of renewable energy resources provides clean energy services for end-users,they also bring about great challenges to the stable operation of power system.On one hand,the low capacity and large quantity of distributed energy resources make them impossible to be centrally controlled by power system dispatch center.On the other hand,the volatility nature of renewable energy resources aggravates the uncertainty of user-side demand requirement,which also increases the security risk of power distribution network.Thus,in order to fulfill the integrated optimization of user-side distributed energy resources,it is essential to improve the utilization and market competiveness of renewable energy,which in turn ensures the sustainable development of renewable energy resources.In this article,we focus on virtual power plant technology and propose novel optimization dispatch theory as well as risk evaluation and management method to provide theoretic support for user-side integration and optimized dispatch.Meanwhile,in accordance with “competitive bidding and open-access selling” principle of electricity market reform in China,we analyze and simulate the bidding strategy and energy transactions strategy optimization problem of virtual power plant.As a vital medium,virtual power plant manages to fulfill the coordination between economy and volatility of renewable energy resources.The contributions of this article could be summarized as follows:Firstly,based on central dispatch mechanism of current power system,this article focuses on internal energy integration and economic dispatch model of virtual power plant.Based on the formulation of virtual power plant,a bi-level optimization problem between virtual power plant and power system dispatch center is established.Through the dynamic adjustment of virtual power plant operation profile,win-win equilibrium between virtual power plant economic profit and social power consumption cost is achieved,which effectively improves the utilization level and economic profit of distributed energy resources.Secondly,to evaluate the multiple uncertainty risk faced by virtual power plant,this article identifies the risk factors of virtual power plant from both of its internal and external perspective,which include the volatility of renewable energy,operation reliability and demand uncertainty.After that,chance-constrained programming is combined with CVaR to conduct risk evaluation of the bi-level optimization between virtual power plant and power system dispatch center.By optimizing the risk aversion level of virtual power plant,equilibrium between economic profit and risk cost is achieved in virtual power plant bi-level optimization dispatch.Thirdly,to analyze the energy transaction strategy optimization problem of virtual power plant in electricity market retail side reform,this article focuses on charging and discharging management problem of plug-in electric vehicles.By simultaneously giving virtual power plant the role of power producer and retailor in electricity market,a Stackelberg Game is formulated between virtual power plant and plug-in electrical vehicles.The optimized Stackelberg equilibrium ensures the highly efficient management and orderly grid-connection of plug-in electrical vehicles.Meanwhile,as a special prosumer,the integration and optimization of plug-in electrical vehicles by virtual power plant contributes to load curtailment and shifting,which also neutralizes the economic and security side-effect brought by renewable energy resources' volatility.Lastly,to analyze the bidding strategy optimization problem of virtual power plant in multiple trading categories of electricity market,this article formulates a joint market trading mechanism consisted of day-ahead and realtime.Through the introduction of game theory,the bidding strategy optimization and profit allocation problems between virtual power plant and other market participators are theoretically solved.By optimizing energy allocation and bidding strategy,virtual power plant manages to achieve profit maximization while simultaneously participates in multiple trading categories.To effectively solve the above problems,multi-scenarios based risk evaluation and management methods are adopted by virtual power plant to reach the equilibrium between economy and risk.Overall,as a promising implementation of distributed energy management and optimized integration,virtual power plant could effectively improve the competitiveness of renewable energy in electricity market.By improving the utilization level of renewable energy,the economic profit of renewable energy is also ensured through the control of virtual power plant,which provides an applicable economic dispatch and optimized integration profile for user-side distributed energy resources.