Research On The Comprehensive Evaluation Index System And Method Of Distribution Network Planning Based On Grid

The planning level of distribution network directly affects the security,economy and reliability level of distribution network.With the continuous expansion of the scale of distribution network,the traditional distribution network planning can not meet the needs of the grid,so the concept of grid planning into people’s vision.To achieve a more complete and refined distribution network decision,This paper proposes to set up an Evaluation Index System and a Study on Comprehensive Evaluation,and analyzes the deficiencies of the current distribution network and the planning effect.This paper discusses the theoretical basis of grid planning and comprehensive evaluation of distribution network.Due to the complex structure of the distribution network system,qualitative and quantitative methods are proposed to screen the indicators.Firstly,qualitative screening was conducted from the aspects of economy,environmental protection,power supply capacity,network structure and equipment level,and then correlation principal component analysis was introduced to conduct quantitative screening of comprehensive evaluation indexes of grid planning.Secondly,Information contribution rate theory is used to verify the reasonableness of selection index system.Finally,the feedback test is carried out according to the dynamic adjustment index system of distribution network,and the construction of grid comprehensive evaluation index system is completed.Aiming at the characteristics of distribution network with multi-level and strong fuzziness,Based on AHP method and grey correlation method,the fuzzy comprehensive evaluation method for distribution network operation level and power supply capacity is constructed by combining subjective method and objective method.The optimal subjective and objective comprehensive weight model based on the least square method was adopted to solve the selection of weight coefficients.The membership function model of each evaluation index was given based on the expert opinions and actual operation of the distribution network.Subordinate Membership degree of each index was calculated using the fuzzy comprehensive evaluation method.Finally,the fuzzy comprehensive evaluation result is obtained,which can find the weak link of power network operation and has a certain promotion value in the evaluation of power distribution network.Considering the super-fuzziness of the fuzzy comprehensive evaluation process,the overlap of evaluation index data information and the correlation of data,a distribution network comprehensive evaluation model based on CRITIC and VIKOR method is established.Firstly,the CRITIC method is introduced to determine the objective weight,and the subjective and objective weight is optimized by the least square method.Then,combined with the VIKOR method,a comprehensive evaluation model is established.Finally,the VIKOR method results ranking of distribution network is obtained,which can solve the priority problem in the planning and transformation of distribution network.The results show that both of the two comprehensive evaluation methods are scientific and valid,which verifies the rationality of the proposed index system and comprehensive evaluation method.Then,by comparing the status quo between different grids and the comprehensive analysis of the results after planning,the weak links in the current distribution network and the effect of grid planning can be reflected scientifically,providing different guidance for distribution network planning.