| Power distribution network with voltage grade,various types of equipment and complex network structure,the operating point area wide,security environment is relatively bad,so the security risk factors influencing the distribution network is relatively more in addition,due to the function of the distribution network is to provide electricity to all types of users,it is safe and reliable operation of distribution network put forward higher requirements.First,Of medium voltage distribution network connection mode,the author of this paper has carried on the thorough research,through the research on development present situation at home and abroad,all wiring pattern to their characteristics and applicable conditions are analyzed and discussed,the research of fujian province and local cities at home and abroad application of medium voltage distribution network connection mode,summary it is concluded that the typical distribution network connection mode advantages and disadvantages applied conditions and the problems existing in the present situation of distribution network connection mode application in fujian province.In addition,the theoretical model of the distribution network was constructed,and the boundary conditions were established as follows: the typical power supply capacity was set as 2×50MVA and 3 × 50 MVA,the load density was set as 5.0 and 40.0MW/km~2,Under this boundary condition,the reliability voltage quality and economy were compared through quantitative results,and the adaptability was qualitatively analyzed In reliability analysis,for all wiring mode considering the average annual failure rate and the faults of equipment of the affected users and mean time to repair,and considering some scheme can transfer load,and then calculate the average power effectiveness(ASAI)as evaluation index,evaluation index of voltage quality for voltage deviation;In the economic analysis,the comprehensive investment of substation line and distribution transformer is converted into the annual value according to the equal annual value method,and then the operation cost is added to calculate the minimum annual cost per unit load as the evaluation index.The adaptability analysis does not need to consider the load density,but mainly analyzes the three aspects of line utilization,power supply security and operational flexibility.This article will get technical economy index and adaptability index gives a more index combining hierarchy comprehensive evaluation index system of power distribution network connection mode,considering the index to the influence degree of the distribution network connection mode is adopted to improve the planning of setting the index weight,and give evaluation criterion and the scoring criteria,based on the Analytic hierarchy process(AHP)According to the comprehensive evaluation methods of process-ahp and Delphi for wiring modes of distribution network,the current wiring modes are comprehensively evaluated and scored according to evaluation criteria and calculation principles to judge their advantages and disadvantages.Finally,considering the current wiring mode and load development of different regions,this paper classifies the power supply regions,and puts forward the optimization scheme based on the comprehensive evaluation results of each wiring mode,so as to obtain the optimal wiring mode of distribution network suitable for each region,and puts forward the construction idea of the wiring mode of medium-voltage distribution network.The significance of this study is to improve the quality of distribution network planning and design,ensure the safe,reliable and economical operation of distribution network,and provide a scientific and reasonable basis for the construction of distribution network. |
PDF Full Text Request