Fuzzy Synthetic Evaluation Method For Planning Size Of Distribution Grid

Sub-transmission and distribution networks construction scale level's evaluation is the electrical network planing and the construction management work new task ,which penetrates unceasingly along with the electricity market reform, is to the power grid development planning macrosopic evaluation. At present the power network planning department has lacked the ways to accurate evaluate the power network construction scale on macrosopic that causes difficulty how to accurate assurance the distribution network construction scale and the items of basic construction priority ,therefore studies the sub-transmission and distribution networks construction scale evaluation method have vital significance.The paper introduced the basic principles of evaluation indices and based on this principle established comprehensive evaluation indices system to describe the planning scale.The paper has separately summarized the research to the construction scale evaluation methods with the statistical analysis method and the mathematical planning method, and carried on the example to study the two method's characteristics.A fuzzy synthetic evaluation method is proposed to evaluate the construction size of power grid. The evaluation process is carried out as follows: the gray theory and mathematical planning method is used separately to establish the model of the fitting degree of scale index and compute their values grade coefficient at first; then subordination value is computed separately; synthesis subordination is obtained with fuzzy computation; the factor weight is calculated by the subjective and objective weighting method,and then the comprehensive evaluation index can be gotten by into account all factor values with the help of summation with weighted method;finally,according to the method of weighted mean to judge the construction size of power grid grade. The example of a local power network construction planning during the period of state ninth five-year is used to validate the proposed method, and the results show it is beneficaial.In order to understand the local power supply enterprise electrical network's construction horizontal as well as current electrical network construction existence question, provide the policy-making basis for the future electrical network plan and the transformation, the evaluation system of area power network building scale based on Web. The system mainly includes seven big functional module respectively based on the user management, the database management, the grey relational analysis, the fuzzy clustering of areas, the statistical analysis evaluation, the mathematical planning evaluation, the Comprehensive evaluation. It uses relations database SQL Server and face the object programming language Visual Studio.NET development environment, has realized the statistical analysis evaluation and the mathematical planning evaluation as well as comprehensive evaluation appraisal result issue and the database management and so on related function. The system has good extendibility and easy maintenance, the user interface is friendly, high performance for man-machine interaction, easy to operate, and so on. The system will provide the electrical network construction transformation basis for the electrical network plan Decision-making body, will also to raises the electric power department's production management level and the efficiency display influential role.