Study On Comprehensive Evaluation Method Of Urban Distribution Network Operating Level And Power Supply Capability

The urban distribution network is directly oriented to the power users,and is an important link for ensuring that users can use electricity safely and reliably.Its operation level and power supply capacity directly affect the power supply reliability and power supply quality of the power system.The “Operational Plan for Distribution Network Construction and Renovation(2015-2020)” issued by the National Energy Administration proposed that optimizing and improving the distribution network structure and eliminating weak links should be the key tasks.Therefore,scientifically assessing the operation level and power supply capacity of the urban distribution network,identifying weak links in the operation of the power grid,and clarifying the direction and reform of the power grid planning have important practical significance for the operation and planning of the distribution network.In order to fully and effectively reflect the operation level and power supply capacity of the city's distribution network,an evaluation index system for the operation level and power supply capacity of the city's distribution network is established.Through the comprehensive analysis of the factors affecting the operation level and power supply capacity of the city distribution network,according to the range and level of evaluation involved,follow the principles of setting the index system systematic,scientific,practical,etc,and establish a hierarchical evaluation index system.Aiming at the multi-level and fuzziness characteristics of urban distribution network operation and the disadvantages of subjectiveness in traditional evaluation methods,this paper proposes a fuzzy comprehensive evaluation method based on AHP-entropy weight method for urban distribution network operation level and power supply capacity..This method adopts a combination weight determination method that takes into account subjective and objective information to solve the problem of weight coefficient selection,and combines the expert opinion and the actual operation of the distribution network to give the membership function model and each model parameter of each evaluation index,using a fuzzy comprehensive evaluation method.Calculate the degree of membership of each index,and finally get the results of fuzzy comprehensive evaluation.The engineering example analysis results show that this method is reasonable and effective.It can find the weak links in power grid operation and can be widely used in power grid evaluation.Aiming at the characteristics of the city's distribution network operation level and power supply capacity evaluation data with large amount of information and many types of data,acomprehensive evaluation model for urban distribution network operation level and power supply capacity based on game theory and grey correlation analysis was established.Firstly,the theory of game theory is introduced,several kinds of weighting results are played,and the optimal weights are obtained scientifically.Then a comprehensive evaluation model is established based on the grey relational analysis method,and finally the grey correlation result ranking of distribution network operation level and power supply capacity is obtained.The engineering example analysis results show that the method is scientific and effective and has good practicability.It can solve the priority of distribution network planning and reconstruction.The above two methods have been effectively evaluated from the two aspects of the weak link and the integrity of the distribution network.Comparison of the evaluation results shows that both methods are scientifically reasonable,and planners can choose according to the actual grid situation and the purpose of the assessment.Appropriate methods are used for assessment,priority is given to the objects whose transformation is extremely urgent,and the distribution network transformation process is scientifically guided.