Comprehensive Evaluation Research On Active Distribution Network Considering Reliability Modularization Analysis

With the rapid development of economy,the demand for electricity continues to grow,which comes from the traditional energy shortage and the increasingly prominent environmental problems.Active distribution network utilizes advanced communication and information technology and power electronic equipment to actively manage the distribution networks with high permeability and distributed energy,realizes the autonomous coordinated control of different kinds and scales of distributed energy equipment,while taking into account the active elimination of renewable energy and the safe economic operation of power system.The application of active distribution network can improve the quantity and operation efficiency of distributed energy grid.To improve the utilization ratio of green energy,to improve the utilization ratio of distribution network assets,to optimize the primary energy structure and to postpone the upgrading of the distribution network,how to evaluate the economic and technical value of the active distribution network project accurately and comprehensively is one of the research subjects to be considered at this stage.Meanwhile,the distribution network is at the end of the power system,and it is an important part of power system to supply and distribute electricity directly to the users.The study of distribution network reliability assessment has remarkable practical significance for improving the quality of power supply and directing the planning,design,operation and maintenance of power system.At present,the high reliability distribution network is facing the goal of standardization and normalization,which has relative independence and multiple combinations in the aspects of grid structure,power supply mode and equipment selection,and has the prerequisite of modular design and splicing.The reliability calculation method based on Modularization is able to simplify the calculation process,to improve the calculation efficiency while taking into account the calculation precision,which is advantageous to the evaluation of the Power distribution network construction level and the economic technology value,and has the value of in-depth research.Based on the current research results of active distribution network and distribution network reliability evaluation method,this paper firstly introduces the characteristics and advantages and disadvantages of typical wiring modes of various distribution networks,and puts forward a method of distribution network connection pattern recognition based on network topology theory and pattern recognition theory.The whole process of distribution network connection pattern recognition is realized by MATLAB software programming.Secondly,on the basis of realizing wiring pattern recognition of distribution network,the reliability evaluation model based on FMEA method is constructed by using each typical wiring mode as the basic module unit,when the reliability index of distribution system side is calculated by the network equivalence method.In MATLAB software,the reliability evaluation algorithm of distribution network based on modular thinking is realized,and the calculation results of the standard FMEA algorithm in different scale examples are compared and analyzed,which proves that the modular method has higher calculation precision and analysis efficiency,so it has certain engineering application significance.Finally,in order to fill the blank in the field of quantitative evaluation of active distribution network,based on the analysis of the core idea and main characteristics of active distribution network,the index system of active degree evaluation is established based on the four-element structure of "source-Net-load-storage" of active distribution network.At the same time,the index system of the active distribution network is composed of the evaluation system of the distribution network Technology index,and the index weights are determined by AHP-Delphi method.By evaluating the active degree index and technical evaluation index of active distribution network in a certain area,the validity and practicability of the proposed comprehensive evaluation model of active distribution network are proved.The results show that the evaluation index can provide the necessary data support for the quantitative analysis of the active distribution network,and provide a useful reference for the further technical route selection of the active distribution network.