Coordinated Optimization Of Demand Response Resources And Related Issues In Energy Internet Environment

The emerging energy internet can not only realize flexible bidirectional interactions between the generation side and demand side in a given power system,but also meet the electricity,natural gas,cold,heat and other energy needs by utilizing the cutting-edge information technology.With the implementation of an energy internet,a multi-carrier energy system will be formed,and the overall energy efficiency and the capability of accommodating volatile renewable energy generation can be significantly enhanced.However,new challenges will be raised,such as coordinated management of massive distributed energy resources(DERs)at the demand side,optimal operation of a multi-carrier energy system with diverse demand response(DR)resources and energy storage devices.With the above mentioned background,the optimal operation of a smart distribution system and a multi-carrier energy system with distributed energy resources extensively integrated at the demand side as well as smart distribution system planning considering interactions among"source-network-load" are studied in this dissertation.In view of the important role of information in the energy internet,related research issues on information production,distribution,exchange and consumption in the energy internet are prospected.The detailed contents of this dissertation are as follows:(1)An intuitionistic fuzzy multiple attribute decision-making method for smart distribution system planning.As many factors need to be considered in smart distribution system planning considering interactions among "source-network-load",the attribute values of evaluation indices can be represented as various forms.Moreover,uncertainty is extensively involved in the evaluation process.In this context,a comprehensive evaluation index system is first constructed from the generation side,the network side and the demand side.Subsequently,the hesitation degree of decision-makers in the evaluation process is well described with the intuitionistic fuzzy theory,and the data types such as the real type,interval type,linguistic type and intuitionistic fuzzy type are processed to the standardized type of intuitionistic fuzzy data accordingly,while the scoring function of the intuitionistic fuzzy number is also improved.Then,the risk appetites of different decision-makers are taken into account based on the prospect theory.Finally,a practical example is employed to verify the feasibility and effectiveness of the proposed method.(2)Congestion management with demand response considering uncertainties of distributed generation outputs and market prices.Despite potential contributions of flexible resources to power system secure and economic operation,uncoordinated operations of them may result in unexpected congestions in the distribution system concerned.The general framework and procedures for distribution congestion management is first presented.A bi-level optimization model for the day-ahead congestion management based on the proposed framework is established.Subsequently,the robust optimization approach is introduced to alleviate negative impacts introduced by the uncertainties of DG power outputs and market prices.The economic efficiency and robustness of the proposed congestion management strategy is demonstrated by an actual 0.4 kV distribution system in Denmark.(3)Optimal operation of multi-carrier energy systems considering integrated demand responses and diversified storage devices.The integrated planning and optimal operation of a multi-carrier energy system are addressed for reasonable utilization of multiple energy resources and maximized accommodation of renewable energy sources.An integrated demand response(IDR)scheme is first designed to coordinate the operation of P2G devices,heat pumps,diversified storage devices and flexible loads within an extended modeling framework of energy hubs.Subsequently,the optimal dispatch of interconnected electricity,natural gas and heat systems is implemented considering the interactions among multiple energy carriers by utilizing the bi-level optimization method.Finally,the proposed method is demonstrated with a 4-bus multi-energy system and a larger test case comprised of a revised IEEE 118-bus power system and a 20-bus Belgian natural gas system.(4)A preliminary investigation on information economics in energy internet environment.Information system represents important part of energy internet,and related information economics in energy internet environment is an important topic to systematically investigate.First,existing energy internet definitions are summarized,and on this basis a prospect on infrastructure,function and operation condition of information system in energy internet is presented.Subsequently,some well-established theories and methods of information economics are briefly clarified.Finally,some issues to be investigated are addressed,including information value-addition and evaluation,information value-addition service mode,information based game analysis and mechanism design.