Research On County Distribution Network Planning Based On Comprehensive Evaluation Analysis

Electric power is an important driving force for urban development,reasonable power grid planning can gain a huge social and economic benefits.In general,the county power grid has many problems,such as,weak structure,poor power supply reliability,power equipment aging,high loss of line,power quality is not stable,low degree of automation,which is far from the construction of a strong smart grid,so the grid planning and transformation is imperative.In the actual engineering case,power distribution system is large,having complex structure and more uncertainty information,so many conventional methods will be limited in practical applications.Based on this problem,this paper applies the comprehensive evaluation and analysis technology to the distribution network planning.Through the evaluation of the status quo and the systematically estimated evaluation of the proposal,determine the feasibility and applicability of the planning program.Compared with the traditional power grid planning method,this method considers more and the effect is more intuitive and more focused on solving the problem of sustainable development of power distribution systems in an increasingly tense environment.This method is of great significance to guiding the power grid construction,ensuring reliable power supply grid,promoting the development of grid quality improvement.The main contents and achievements of this paper are as follows:(1)Based on the research of power grid planning and comprehensive evaluation,this paper constructs a comprehensive evaluation system of power grid planning based on technicality,economy,adaptability and coordination,and uses expert judgment method +Fuzzy chromatographic analysis to set up the authority of index and apply the grid comprehensive evaluation system is to the power grid planning.Taking the L county power grid project as an example,in the high voltage grid planning,through the quantitative comparison and comprehensive comparison of the index in the evaluation system,select the suitable high voltage grid planning program which adapts to future development of L County,and the low-voltage distribution network was planned.(2)In this paper,the status and operation of distribution network in L County are analyzed,and some problems existing in power supply capacity,power grid structure,power equipment and construction environment of L County distribution network are summarized.(3)In this paper,the basic characteristics of load forecasting,influencing factors and load forecasting methods are introduced in detail,and a combination coefficient method based on analytic hierarchy process is proposed.Verified by example,this method is more effective than single model load forecasting Method,the average weighted combination coefficient method,and the variance-covariance combination coefficient method.Then through the combination of analytic method based on analytic hierarchy process,The electricity demand of L County was forecasted.(4)In this paper,a long-term high voltage grid for L County is planed,which plays a guiding role in construction of thed future power grid.(5)This paper execute the electrical calculation analysis,verify the feasibility and practicality of this plan.