| Affected by the randomness and intermittent nature of wind,there is relatively serious cuitailment of wind power in China.In order to improve the overall utilization efficiency of energy and the ability to utilize renewable energy,the demand for multi-energy integration is becoming more and more urgent.The"Integrated Energy System(IES)"is a powerful step being proposed to adjust energy structure.From the perspective of improving wind power utilization and operational flexibility of IES,this paper studies two key issues of IES scheduling.On one hand,power to gas(P2G)technology provides a new way to eliminate wind power by converting excess wind energy into easy-to-store natural gas,and will be one of the important technologies for IES in the future.On the other hand,by refining the dynamic characteristics of gas and heat in IES,using the inertia of gas and heat to convert electricity into other forms of energy storage,the problem of wind cuitailment will also be greatly solved.Therefore,in the context of the difficulty of wind power utilization,this paper discusses the optimization operation of IES from two aspects:P2G technology and dynamic characteristics of gas and heat.The core work and innovative contributions are summarized as follows:Firstly,the three-tier architecture of IES and its respective components are introduced,including inter-regional,regional,and user-level IES.For the regional IES studied in this paper,the mathematical models of key components in IES are introduced,including the power system,natural gas system,thermal system and coupled component model;on this basis,a common model of IES modeling,energy hub(EH)model,is introduced.This part of the content can provide theoretical basis for the IES optimization scheduling and simulation verification.Then,considering the operational cost of P2G,this paper analyzes the influence of P2G on wind power utilization and operational economy of the IES.A multi-objective optimal day-ahead scheduling model is proposed to coordinate the contradiction between its higher operational cost and better effect in eliminating wind power.The models of P2G and its operational cost are established,and the model of energy hub including P2G is given.In view of the high operational cost of P2G,the contradictory relationship between the operational economy and the wind power utilization is coordinated by the multi-objective weighted fuzzy programming method.The model is simulated in an IES including 9 energy hubs.The results have verified the importance of considering the operational cost of P2G and the feasibility of considering operational economy and wind power utilization together in the IES.At last,a scheduling model considering dynamic characteristics of heating and gas networks is proposed to study their impacts on the operation of the IES.The dynamic characteristics of heating and gas networks are modeled and analyzed,and their energy storage capacities are explored.An optimal scheduling model of the IES was established and transformed into a linear problem to solve.The impact of the network dynamic characteristics on the system operation are simulated by the case study,and the interaction between different dynamic characteristics and the potential benefits of the collaborati-ve optimization are analyzed,which pro-ve the necessity and feasibility of considering the network dynamic characteristics into the operation of IES.The research on optimal operation of the IES considering wind power utilization,is helpful to coordinate the unified scheduling of electricity,gas and heat systems and realize the mutual complementarity of different systems.It is the key to to improve the operational flexibility and wind power utilization of the whole system.And it is an effective way to improve the economy and safety of the entire system.This paper makes a preliminary exploration of the optimal operation of IES under the background of wind power curtailment.Hoping that the relevant results of this paper can provide an effective reference for the development of IES. |
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