Research On Integrated Optimal Scheduling Problem Of Micro Energy Network

As the rapid development of the economy,the demand of energy is increasing.How to deal with the shortage of energy has attracted the attention.The development of distributed energy system provides a convenient way to make full use of renewable energy.Micro-grid is widely studied while it includes distributed generations such as PVs and wind turbine.However,it is only used to provide the electricity and the utilization of the single form of energy is not benefit to improve energy efficiency.On the other hand,the demand of users are more and more diverse.Starting from microgrid,this paper studies the integrated optimal scheduling problem of micro energy network system which includes electricity,gas,cold,heat and other energy forms,including the energy management system(EMS)optimal scheduling problem of microgrid and the EMS optimal scheduling problem of micro energy system based on the micro-grid.The distributed integrated energy system can be regarded as a small grid in the energy network.It can operate as an independent system,and it can be also connected with the external energy market.The main problem of EMS optimal scheduling is to determine the optimal scheduling objective and constraints,and then establish an optimal scheduling model,considering the prediction of the demand and distributed energy generation.The main work of this paper can be summarized as follows:(1)Propose the hybrid model of EMS optimization scheduling method for microgrid,which includes photovoltaic cells,diesel engines and batteries.Firstly,it introduces the EMS framework and the system model of the micro-grid,then it proposes the EMS optimal scheduling model based on the system model of micro-grid,and chooses maximizing supplier's revenue as the optimal objective,which is equal to the difference between the expenses charged to the users and the cost of system operating.Maximizing the revenue is same as minimizing the cost when the demand of users is invariable and not influenced by the price decided by the supplier.Then the optimization problem is formulated as a mixed-integer quadratic programming problem,and considering the inaccuracy of the predictions of the demand and PVs output,it chooses the rolling optimization strategy to solve the optimal problem.Based on the micro-grid EMS optimal scheduling method,the basic software is developed,which is used to model and simulate the micro-grid EMS optimal scheduling problem.The main functions of the software include setting up a micro-grid optimization scheduling problem model,forecasting input parameters,setting system parameters,and computing the optimal scheduling problem.(2)Propose the integrated optimization scheduling method for micro energy network system EMS with different targets,which includes electricity,gas,heat,cold and other energy forms.This chapter introduces the EMS framework and system model of the micro energy network system firstly,and then considering that different energy forms have different energy grades,respectively proposes the integrated optimal scheduling models for economic operation and minimum entropy based on the model of micro energy network system.For the same micro energy network system model,two optimization scheduling methods are applied and two simulation optimization results are compared for the futher research of comprehensive multi targets optimal scheduling problem.(3)Propose optimal scheduling method for the user side management(USM)of the micro energy network system EMS.Distributed generations have strong randomness while photovoltaic cells are strongly influenced by weather and temperature,so it is difficult to meet the users' demand to some extent.The energy comprehensive optimization scheduling method for USM can adjust the user's demand,balance energy consumption and improve the network reliability.Real time pricing(RTP)is an important means for the user side management,and this chapter proposes the micro energy network system optimization scheduling model based on RTP firstly.To solve the problem that the randomness of the distributed generations,it chooses the rolling optimization scheduling method based on Monte Carlo simulation,and compares it with the simulation results using the rolling optimization method introduced before,and it can be concluded that this method is more effective to solve the problem of the randomness of distributed generations.