Research On Energy Efficiency Assessment And Grid Structure Optimization Of Distribution Network

Distribution network is an important part of the power grid and the key to the implementation of energy efficiency management,loss reduction and energy saving.Therefore,the improvement of energy efficiency of distribution network will have a far-reaching impact.The grid structure is the "tendon" of medium-voltage distribution network,and the optimization of grid structure is the basis of safe,reliable,economic and high-quality operation of the grid.The scientificity and rationality of urban distribution network structure not only concerns the reliability and economy of power grid operation,but also directly affects the beauty of the city and the development of the city economy,and more importantly,the quality and level of the material and cultural life of the masses of the people.China's distribution network is large in scale and there are many network connection modes,but the rational selection of connection modes has not been discussed in depth.Because of the disadvantage of confusion and disorder in the connection mode of distribution network target grid,the grid structure is one of the key points in the planning and transformation of urban power grid.This paper optimizes the distribution network structure from two aspects of distribution network technology evaluation and wiring mode,and pays attention to the practicability of distribution network wiring mode.Taking typical distribution network in actual area as an example,this paper puts forward the optimization schemes of different wiring modes,so as to realize the energy-saving transformation of distribution network.According to the relevant standards and norms and references to relevant literature,an energy efficiency index evaluation system for distribution network is established,which covers the transfer capacity,power supply quality,power supply capacity,transformer equipment and technical equipment.The evaluation method uses the analytic hierarchy process to calculate the weight of each index in the index system,and combines the actual value of each index,obtains the total score of the evaluation object,and according to the score.The size of the distribution network to identify weak links,select different wiring mode of power supply model to optimize it,in order to find the optimal target network.In the process of grid optimization,how to determine the optimization scheme of the grid so that it can not only adapt to the development of urban load,but also meet the requirements of users for power supply quality and reliability is the key problem of optimization.Firstly,this paper reviews the typical wiring modes at home and abroad,summarizes the advantages and disadvantages of each wiring mode and its application occasions,and establishes the power supply model schemes of different wiring modes according to the actual situation of the power supply area and the commonly used ways of line transformation,including line cut-off,new wiring,double power supply transformation,large cross-section wire replacement and so on,so as to realize the optimization of the grid.Finally,a practical power supply area is selected as a representative to carry out case study of distribution network optimization.Through collecting,sorting out and calculating the data in this area,the comprehensive energy efficiency score of the grid structure in this area is calculated by using the energy efficiency index system of distribution network,and its weak links are found out.Several lines with prominent problems are selected,and a reasonable connection mode optimization scheme is given to optimize the grid structure.