| The Integrated Energy System can absorb new energy sources such as wind and light,and it is a unified carrier to realize the organic combination of electricity,gas,heat,cold and other energy types.It can solve the problems of low energy utilization efficiency and environmental pollution,which is an important direction of energy system development in the future.At the same time,the interconnection of heterogeneous energy brings new challenges to the operation of integrated energy system.The nature of different types of energy is different,so it needs to be studied according to their own nature classification.Because the system contains various equipment and energy coupling is very close,the uncertainty factors increase a lot,and the influence range is more extensive.According to the above,the following work is mainly carried out in this thesis,aiming at the optimization scheduling problem of the electric gas and thermal coupled integrated energy system.Firstly,the research status of integrated energy system optimization operation at home and abroad is introduced,and the progress of system modeling,optimal scheduling and uncertainty research is summarized respectively.It is found that the current research of integrated energy system seldom involves the research of pipeline characteristics in natural gas network and the consideration of energy storage equipment recession cost is also neglected.Secondly,a refined integrated energy system model considering pipeline characteristics is established.The power system network and power generation equipment are modeled,especially the battery equipment is studied,and the operation model considering single action recession is established.Considering the slow flow of natural gas in the pipeline,a natural gas network model considering the characteristics of the pipeline is established,including the node pressure pipeline flow relationship and pipe storage phenomenon.The model of common coupling equipments are given,and the operation model of the system is obtained,which describes the operation characteristics of heterogeneous energy network.Then,based on the above model,the day ahead optimal scheduling model of integrated energy system considering pipeline characteristics is established.According to the demand of power,gas and heat loads in the dispatching cycle,combined with the basic operation constraints of power system,the basic operation constraints of natural gas system including pipeline characteristics and the operation constraints of coupling equipment,the objective function of minimizing the total operation cost of the system is proposed.Through a specific example,the total operation cost,unit operation status and battery output of the system are analyzed to verify the effectiveness of the model.Finally,considering the uncertainty in the system,a two-stage distributionally robust optimal scheduling model is established.Considering the difference and characterization of the uncertainty of wind power output and load in the integrated energy system,the probability distribution set and trapezoidal fuzzy set are used to represent the two kinds of uncertainty factors respectively.On this basis,combined with the integrated energy system model considering the characteristics of pipeline,based on the relevant optimization theory of distributionally robustness.The distributionally robust optimal dispatch model considering the uncertainty of wind power output and the distributed robust optimal dispatch model considering the bilateral uncertainty of source and load are established respectively.According to the non convex and nonlinear characteristics of the model,auxiliary variables are introduced to linearize the model.The C&CG method is used to solve the problem.By comparing the optimization results of different models,it is proved that the system can effectively deal with the uncertainty scenes and maintain the stable operation of the system through the coordinated action of coupling equipment and network. |
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