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Research On Optimization And Comprehensive Assessment Method Of Distribution System

Posted on:2006-04-16Degree:MasterType:Thesis
Country:ChinaCandidate:D ZhangFull Text:PDF
GTID:2132360155969335Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
With the fast development transformed to the distribution network in urban and rural areas of our country, people have already realized progressively the important meaning of seeking to transform the scheme in investment decision and newly-build network through optimizing planning in power system. Because the specific area influenced by such comprehensive factors as the environment, economy, development potentiality, etc., the making of the good distribution network planning concerning cost of investment, economic benefits, impacts on surrounding area and economic development speed of this area in future. A great deal of influence factors exists in the course of planning of the distribution network. To handle the relations of various fields well correctly, an efficient and scientific comprehensive assessment system is badly needed. For this reason, this thesis uses Ant Colony Optimization Algorithm (ACO), network equivalence method, and with the aid of the power system analysis software package, to carrying on research on some key problems.(1) Distribution network optimizing based on ACOThe network optimizing is a main content in urban distribution network planning, which has been widely researched. This thesis has taken into account the load rate of branch road in the goal function of the total expenses of network, reflecting the situation of every branch in the network on the whole. The higher the load rate is, the easier it is chosen. This concept improved the validity of the system.The ACO is a kind of new heuristic method; it searched for the best result through apperceiving the density of pheromone on the route. This thesis analyses the stagnant phenomenon in the basic algorithm and then introduce the little interferer. This method seeks the change of the pheromone density on route of every stages in searching course, adjust the release tactics of pheromone dynamically through a large number of artificial experiments, which helps to solving more complete search in the space.(2) Evaluation reliability of a distribution networkThis thesis adopts equivalence recursive algorithm based on the radiation structure of the distribution network to get the evaluation reliability of system. This method combines equivalence law with recursive law. A distribution network is stored as a node of binary tree first, then realized successive network equivalents through post order recursive traversal, and makes complex sub-feeders to a equivalent lateral section so reduces a complex multi-layers distribution network to a simple one layer radiate network. In the course of preorder recursive traversal, the calculate formulas will be transferred to calculate the systematic reliability indexes.(3) Comprehensive assessment methodThis thesis sets up the evaluation system of the distribution network, puts forward the Interval-based Analytic Hierarchy Process (IAHP) as the decision method of comprehensive assessment for distribution network. After having carried on further investigation on model and method of the IAHP, it points out the application principle when solving the weights. The thesis simplifies this complicated problem of comprehensive assessment decision of distribution network scientifically and takes advantage of expertise and numeration.
Keywords/Search Tags:Distribution network planning, Ant Colony Optimization Algorithm, reliability, Interval-based Analytic Hierarchy Process, comprehensive assessment
PDF Full Text Request
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