Economic Benefit Of Planning Scheme And Reliability Evaluation Of Medium Voltage Distribution Network

The distribution network is the connection link of power system with many power consumers and its status and role is irreplaceable.The economic benefits evaluation of distribution network planning can provide important guidance for the choice of planning scheme,so that the construction of distribution network in the future will be more economical and reasonable.Reliability evaluation of distribution network can fully find the weak link of the distribution network,as well as the potential problems,to facilitate the maintenance of the power distribution network,and provide information for the future expansion and transformation of the power grid.Therefore,it is necessary to carry out the economic benefit and reliability evaluation of medium voltage distribution network.First of all,the evaluation of the economic benefits of distribution network planning is carried out.The index system of benefit evaluation is established from three aspects: technical and economic benefit,project financial benefit,social and environmental benefit,and the whole life cycle theory is introduced to analyze the financial benefit of the project.The determination of index weights is based on interval analytic hierarchy process,which makes the weight value more reasonable.The evaluation method is based on the model of fuzzy theory.Through the analysis of the specific examples,the results show that the economic benefit evaluation model based on interval analytic hierarchy and fuzzy theory is feasible.In other words,this method can effectively evaluate the economic benefit of the distribution network planning.Then the reliability evaluation index of distribution network is determined.In view of the network structure and characteristics of distribution network,and the various factors that affect the reliability of the distribution network are systematically analyzed.The reliability index of the load point which is needed to evaluate the reliability of distribution network is established,and the reliability calculation of the typical network structure is introduced.Finally,the evaluation method of the minimum path is used to evaluate the reliability of distribution network.The basic concept of the breadth first search method and the minimum path assessment method is introduced in details.The evaluation method based on the minimum path is introduced into the reliability evaluation of distribution network,and the feasibility of the method of reliability assessment based on the path method is verified by the analysis of the actual cases.Besides,the concrete measures to improve the reliability are summarized from four aspects.