Research On The Methods Of Dividing Distribution Network Into Units And Evaluting Planning Projects

Under the environment of power system reform vigorously implemented by the power grid company,more and more social capital has been introduced into incremental distribution network and electricity sales,which undoubtedly raises the difficulty and requirements of planning distribution network.On the one hand,the power grid company not only needs to improve their investment management level under the external competitive pressure.On the other hand,higher requirements for the transparency and refinement of regional distribution network planning have been put forward.Therefore,the power grid company must establish the concept of efficiency-benefit-centered investment,coordinate all aspects of power grid development,optimize the investment structure and timing,and focus on maintaining control.The principle of unit planning is an important way of thinking and technical means to solve these problems.Deepening the unit system planning technology is of great significance to solve the problems of polarization,investment island and management limitation in the current distribution network planning.In view of the above problems,this paper proposes a complete distribution network planning method based on unit planning,which includes the methods of dividing units and rationality evaluation,the evaluation methods of distribution network planning projects effectiveness and research on the optimization scheme of multi-dimensional planning projects.In the section of the methods of dividing units and rationality evaluation,firstly,the relevant research results of unit planning are analyzed from the aspects of significance and purpose.By drawing on and absorbing the relevant and current theories of grid planning,the unit division method combining the methods of road network and grid network is determined,so as to realize the complementarity of advantages and disadvantages of these two,and ensure the scientific results of dividing units.Then,the principle of dividing units is analyzed,and the principle is refined one by one,and the indicators for evaluating the reasonableness of dividing units are refined.Thus,a complete system from the method of dividing units to reasonableness evaluation is formed,and the process of dividing units from scratch to refinement is realized.In the section of the evaluation methods of distribution network planning projects effectiveness,according to the specific requirements of distribution network planning during the 13 th Five-Year Plan period of the power grid company,the main idea of distribution network planning in units is determined with precise investment strategy.Aiming at the requirement of precise investment in distribution network construction that priority should be given to the present situation of target power grid and related policies,the evaluation index system of distribution network planning project effectiveness based on the results of the present situation and policy analysis results is selected.Combining indicators in national and enterprise tenders to supplement membership functions and the method of analytic hierarchy process(AHP)to determine the weight of indicators,the evaluation index system is improved and a complete evaluation process for the effectiveness of planning projects is formed.In the section of research on the optimization scheme of multi-dimensional planning projects.This part is based on the research results of the two parts above.Firstly,by introducing the concept of project attribute,the qualitative relationship between the planning projects and the evaluation indexes of effectiveness is established.Combining with various methods of basic data processing and the planning projects plan formed by the exhaustive method,the purpose of raising the qualitative relationship between the two elements to quantitative relationship is realized;Then,based on the quantitative relationship,a mathematical model for optimum selection of planning projects with the highest score of the effectiveness evaluation as the objective function and multiple constraints is formed by combining with the method of calculating the score of the second part;Finally,genetic algorithm and other data processing tools are used to solve the mathematical model,and the results of the model can realize the optimization of unit planning project schemes in multiple dimensions,thus the problem of how to maximize the investment benefit of distribution network under limited resources will be solved.Examples are provided at the end of each chapter for verification.