Study On Reliability Evaluation And Operation Optimization Of Multi-energy System

In order to mitigate the extreme climate hazards caused by global warming,more and more countries have taken carbon neutrality as an important part of their climate actions.In this context,the energy Internet with low-carbon transition,multi-energy complementarity,and information integration is an important technical means for carbon neutral action.Energy Internet realizes flexible production and dispatch of energy supply by integrating energy network with transaction network and information network,aiming at economy,environmental protection,renewable energy ratio,and energy storage ratio.At the same time,the complex coupling relationship exists in the multi-energy complementary system represented by the energy Internet,which makes the planning and investment operation mode of the energy system become more and more complex.The system involving multi-energy storage has scheduling problems on multiple time scales.The energy storage capacity will have a direct impact on the capacity planning of the system and the scheduling scheme per unit cycle,and then affect the system economy,environmental protection and other indicators.Renewable energy is generally subject to the limitations of natural and spatial conditions,and has the problem of unstable output supply.Therefore,how to systematically,comprehensively and efficiently evaluate the reliability of multi-energy complementary systems under the background of energy Internet has become a research hotspot.In this paper,under the background of energy cloud technology theory,can complement each other for quantitative analysis system,the stored energy and renewable energy configuration capacity proportion(i.e.,allocation ratio)on the system scheduling strategy,in turn,influence on the reliability of the power,set up an energy storage layer of flexible scheduling for optimization model,based on temporal markov process of two state model for the outer layer model of two phase can complementary system operation optimization and reliability evaluation method.The main work is as follows:The development trend of energy system under the background of international carbon neutral action is described,and the academic research results of operation optimization and reliability assessment of energy system at home and abroad are summarized.First of all,combined with energy cloud technology,starting from the energy coupling status of the multi-energy complementary system,using the energy hub model as the basic structure,in-depth analysis of the coordination and transformation relationship among various forms of energy such as cold,heat,and electricity;Then a brief description of several commonly used multi-objective optimization and reliability evaluation theories for energy systems at this stage is briefly described.Finally,the reliability index system of regional multi-energy systems is sorted out to lay a theoretical foundation for the next step of establishing scheduling optimization and reliability evaluation.Taking the optimization of the operation scheduling of the energy system as the inner model,and taking the life-cycle operating cost and environmental protection indicators as the optimization objective function,the energy storage is analyzed in depth according to the output characteristics and seasonal characteristics of the energy conversion equipment in the energy system.As well as the operation mechanism of other energy equipment,the decision variables are introduced to dynamically describe the energy storage,discharge and equipment output status of the energy system at each time period;each single objective optimization adopts the MILP mixed integer linear programming algorithm,and then based on the NSGA-Ⅱ multiobjective optimization algorithm,To obtain the set of Pareto equation solutions,so as to realize its optimal scheduling,and finally determine the optimal solution based on expert evaluation based on the distance method of superior and inferior solutions.Establish a continuous time Markov two-state model for various energy conversion devices in the multi-energy complementary energy system,simulate the operation and failure states of each device on the time scale of the whole life cycle,formulate the priority of energy conversion devices,and establish the standby energy response mechanism for various faults.Taking the optimal solution determined as input and combining with the random state model of energy conversion equipment mentioned above,the reliability indicators are finally counted and calculated.Energy planning for a park based on specific cases:(1)Combined with the annual load distribution law of the park,four groups of typical load rates were selected to optimize the scheduling of the energy planning scheme and evaluate its reliability.(2)To explore the capacity of energy storage device for the efficiency of energy planning,environmental protection and reliability,the influence of the energy storage than as independent variables,economic indicators such as the dependent variable,the calculation shows that the whole life period cost reduced gradually with the increase of the energy storage ratio,environmental protection is also improved,reliability indicators are improved,but its growth there is difference.(3)After the energy storage device is introduced into the energy system,there is some flexibility in the selection of the total configuration capacity of the energy system due to various considerations;As a new type of equipment to adapt to the requirements of sustainable development strategy and low carbon emissions,the energy efficiency ratio of the sea water source heat pump is greatly affected by the sea temperature,and the configuration ratio of the energy system economy and other indicators has a greater impact;In this paper,the selection set of energy system configuration scheme is constructed based on three factors,total configuration capacity and specific storage ratio of sea source heat pump configuration,and each scheme is objectively scored by combining the advantages and disadvantages solution distance method,thus providing theoretical guidance for the selection of scheme.