| Distribution network plays the role of receiving electric energy transmission network and distributing electric energy for users in the power system.It is an important link to ensure the safe and reliable use of electricity for users.Its running condition and power supply capability have direct effect on the power supply quality and running reliability of power system.Therefore,it is of great theoretical and practical significance to scientifically evaluate the comprehensive operation ability of distribution network and find out its weak links as the basis for daily management of distribution network and implementation of transformation projects.This paper firstly expounds the basic theory of comprehensive evaluation,from characteristics of distribution network operation,analyzes the factors affecting the level of distribution network operation,selected in line with the characteristics of distribution network operation evaluation index,according to the guiding ideology of hierarchical level,guarantee the satisfaction of the customers and the power supply company under the premise of the interests of both sides,to select the index set,affect the ability of the distribution network operation of each evaluation index are explained in detail.Based on the status quo of distribution network structure,development coordination ability,operation efficiency and economic benefits of power grid companies,a set of distribution network comprehensive operation index evaluation system satisfying the construction principle of the evaluation system is constructed.Secondly,aiming at the multi-layer and fuzziness of distribution network operation,this chapter proposes a fuzzy comprehensive evaluation method of distribution network operation based on combined weight assignment.In order to avoid single weight determination method and unreasonable weight result,Delphi method and analytic hierarchy process were used to determine the subjective weight,entropy weight method was used to determine the objective weight,and the evaluation method was used to determine the weight coefficient.Combined with expert opinions,the index set and evaluation set are determined,and the comprehensive fuzzy evaluation model of the county distribution network is constructed under the guidance of fuzzy theory,so as to analyze the operation status of the distribution network in a complete and detailed way,and realize the purpose of investigating the potential weak links in the distribution network.Based on the established distribution network evaluation system,SoTower computing platform was used to score the distribution network operation,and the feasibility of the proposed model was verified.Finally,in order to improve the unreasonable distribution of the importance of subjective and objective weights in the evaluation index system,game theory was introduced to make the two weighted results play games with each other to obtain the Nash equilibrium solution and determine the optimal combination weight.Considering the uncertainty of load access in the operation of distribution network and the large amount of data in the evaluation process,this paper introduces the grey correlation method to quantify the order relations among all levels of indicators in the evaluation system,constructs the grey correlation comprehensive evaluation model of distribution network operation,and obtains the grey correlation results.Combined with an engineering example,the paper analyzes the weak link of a county-level distribution network in hebei province and puts forward the improvement measures. |
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