Energy Flow Calculation Of Integrated Energy Network Based On Improved Newton Method

With the progress of science and technology,humans’ living standard has been improved,and the single energy structure cannot meet the needs for human production and life.At the same time,the depletion of fossil fuels and the pollution of environment is also a significant issue in front of mankind.In order to solve the relevant problems,the integrated energy network assembling multiple energy forms and coupled with various energy networks has emerged.The calculation of energy flow in the integrated energy network is a vital process to understand the state of the network.It is an important basis in network control,fault analysis and other processes.Based on the principle of power flow calculation in power systems,this thesis proposes a corresponding method for the calculation of energy flow in integrated energy networks to ensure an accurate and rapid calculation.Detailed research contents are described as follows:1.According to the physical structure and operation mechanism of an integrated energy network,the mathematical model of energy transmission in the power network,the natural gas network and the thermal network,are established respectively.After a long-term study of the interconnection between networks,more comprehensive types of coupling device are proposed.The mathematical model of energy conversion is established for foundation of energy flow calculation.2.The energy flow of an integrated energy network is calculated by Newton method and the interaction between the networks is analyzed.A method of energy flow calculation based on we-energy is proposed.We-energy is an integrated mode of energy production and consumption.It integrates energy production,energy storage and energy consumption.This thesis gives a we-energy model based on device efficiency.And two numbering methods are adopted to simplify the calculation process of energy flow in terms of global and local views.3.Referring to the initial value sensitivity issues of Newton method,this thesis proposes a convergence theorem of Newton energy flow which contributes to develop a novel selection method of the initial value and is applied in the integrated energy network.Meanwhile,the proposed maximum iterations estimation theorem can ensure the rate of convergence.Two theorems proposed can be used to determine the convergence before calculation and directly select optimal initial guess from the feasible region.And the correctness and validity of the theorem is proved by simulation.4.In order to solve the problem for low computing speed and high requirements of computing equipment in large-scale integrated energy networks,a distributed parallel computing method suitable for integrated energy networks is applied.By splitting the coupling nodes,the whole network is decomposed into many sub networks.At the same time,multiple processors are used in parallel computing to improve the computation speed of energy flow and reduce the demand for a single processor.At the end of this thesis,the research contents and the results of the study are summarized,and the future research direction of the integrated energy network is also discussed.