Urban Mid-voltage Distribution Network Planning Decisions Based With The Risk Indicator

Urban mid-voltage distribution network is an important public infrastructure of national economy and social development,as the end of the power system,bear the task of providing electricity directly to the user,Therefore,a reasonable planning of the city in the distribution network is its users to provide high-quality power of a strong guarantee.At present,in the field of urban distribution network planning,the focus is on planning methods and planning options,but for the merits of the planning program is not a more comprehensive measure.Based on the planning of mid-voltage distribution network in a city economic and technological development zone in northeast China,this paper studies the priority of planning area planning under the known power supply reliability statistics,the selection of mid-voltage distribution network connection mode and Comprehensive assessment issues and evaluation of power grid planning solutions.Aiming at the problem of determining the priority of distribution network in a city economic and technological development zone in northeast China,based on the reliability statistics of power supply,the planning area is divided into multiple independent power supply partitions according to the main transformer substation of the substation.Based on the principal component analysis the reliability evaluation model of the power supply provides a reliability evaluation of multiple power supply zoning,and the planning priority of each power supply partition is obtained according to the evaluation result.By drawing the index satisfaction and importance area map of each power supply partition,it provides a theoretical basis for distribution network planning.According to the engineering example analysis of the priority of the distribution network in the economic and technological development zone,the validity of the method is verified.Based on the basic requirement of satisfying the safety of the mid-voltage distribution grid,the selection model and rule base of the mid-voltage distribution network are established according to the basic connection theory.Based on the model and the rule base,the Visual Studio 2010 tool platform has been developed mid-voltage distribution network connection mode selection software;According to the distribution network planning boundary conditions set the software parameters,to meet the basic requirements of distribution network connection mode;In order to evaluate the connection,paper focuses on the analysis of the comprehensive evaluation index system of the connection mode from the point of view of risk,reliability and economy,introduces the fuzzy membership degree function to the index value,and obtains the comprehensive score of the connection mode to be evaluated.Finally,an example analysis of the connection method in the power supply area of the open area proves the rationality of the method.From the perspective of grid risk,power supply reliability,economy and coordination,it constructs a comprehensive comprehensive evaluation index system of planning grid;In order to evaluate the risk level of the planned power grid,a risk assessment method of the distribution network considering the potential risk of the structural defects of the grid structure is introduced.By establishing the risk index system of the grid,combined with the calculation and risk level of the risk quantification to determine the comprehensive risk level of the planned power grid;Based on the planning requirements of coordination and distribution of distribution networks,the coordination of the planning grid is evaluated from the aspects of the capacity and load balance.Finally,the concrete implementation steps of planning the grid assessment are given,and the validity of the method is verified by the engineering examples of two planning schemes in a planning area of the Economic and Technological Development Zone,which is of guiding significance to the planning and decision making of the planning grid.