| The transformation of energy structure aiming at carbon neutralization and carbon peaking will have a profound influence on the morphological evolution of power system.With the increase of the access proportion of renewable energy,the large-scale withdrawal of thermal power will lead to changes in the operation and dispatching mode of electric power system.The operation scenarios of electric power system are complex and changeable,and the dispatching operation,planning and construction management face new challenges,which puts forward new requirements for the compilation of practical simulation tools of electric power system.Many problems faced by the power system will significantly affect the evolution path of the power grid,the future energy pattern and the form of the power grid.Therefore,it is necessary to study the new law of the development of the power grid from a global perspective,scientifically and accurately study the evolution path of the power system,and provide theoretical support for the decision-making planning of the power grid in the future.Therefore,combining regional endowments and national policies,it is of great significance to develop practical tools for medium-and long-term power grid evolution and scientifically study and judge the direction of power grid development.In this paper,considering the energy development trend,a grid evolution model considering the transformation of energy structure is established,and the generation method of typical scenarios of high-proportion renewable energy power system is studied.The evolution scheme is extended and analyzed and evaluated.The analysis and evaluation results of the evolution path are provided according to the typical grid examples at home and abroad,and the effectiveness of the method is verified.The main research contents and innovations of this paper are as follows:(1)The main links of energy structure change in the power system are analyzed,and the load scale prediction model considering electric energy substitution on the power side is established.The influence of energy structure change on the development scale of source and charge and the evolution path of the power grid is analyzed by considering the development of advanced technology and clean substitution in the process of energy transformation,which lays the foundation for the construction of the overall evolution model.In the study of the operation scenario of the power system with high proportion of renewable energy,a scenario reduction method considering the time-sequence matching of the source load was proposed,and the operation simulation scenario set was generated considering the time-sequence matching characteristics of the renewable energy output,which provided the basic analysis scenario for the production simulation calculation simulation of the power system and the grid evolution simulation.Based on the above work,a medium-and long-term power supply growth optimization model considering clean substitution was constructed to plan the installed capacity growth of various power supply types in the medium-and long-term main grid,so as to provide boundary conditions for power grid evolution.This paper studies the network growth and evolution mechanism based on complex network theory.After investigating the factors affecting the growth and evolution of power network nodes.it divides the power network into local world based on geographic information clustering.proposes the source load spatial decomposition method considering regional characteristics,discusses the differences in the evolution of power network topology structure with different characteristics,defines the concepts of power network node optimization factor and grid node distance.The method flow for node growth and evolution of power system is given.(2)In the process of power grid evolution,low-level data generation and upper-level program evaluation need to conduct short-term production simulation.The change of energy structure brings new challenges to the operation and planning of power system,which requires the support of refined production simulation and evaluation technology.Firstly,a scenario set generation method based on clustering coupling was proposed to generate typical power grid operation scenarios,and a refined production simulation model including large-scale power system was established.A new scheduling mode involving wind-light load reduction and backup was adopted.The objective function considered the unit start-stop cost,system backup cost,carbon emission cost and other indexes.And the operating cost characteristics of high proportion new energy power system are analyzed and studied.In addition,in order to evaluate the power grid evolution scheme,taking into account the four aspects of economy.reliability.flexibility and environmental protection,an evaluation index system of power grid medium and long-term evolution scheme based on multi-stage planning is established.(3)The implementation of power grid evolution tools needs the guidance of the overall theoretical framework.The evolution mechanism of the traditional OPA model is studied,and the traditional OPA model is improved from the aspects of slow process and fast process in combination with the above studies on all aspects of power grid evolution,and the grid evolution framework based on the improved OPA model is established.The evolution process is divided into three stages:initial backbone power grid data survey,timing planning of source load scale development of backbone power grid,and power grid evolution analysis.The power grid line upgrading method is studied and proposed from two aspects of line upgrading alternatives and optimization algorithms,providing a theoretical basis for power grid evolution tools.According to the actual data of power grid,a case analysis of power grid evolution is carried out from two aspects of evolution section analysis and evolution scheme effect evaluation.In summary,this paper constructs a refined grid evolution model that is oriented to medium and long-term time scales and includes large-scale renewable energy sources,which provides a theoretical basis for the study of grid evolution tools and policy suggestions for future grid development. |
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