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The Research On Reactive Power Optimization In Distribution Networks Including Wind Power Generators

Posted on:2014-02-06Degree:MasterType:Thesis
Country:ChinaCandidate:K FengFull Text:PDF
GTID:2232330398974700Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
Wind power generation, because of its flexibility, less investment, and little pollution, has caused global concern, is now becoming the focus of electric power industry, and has an extensive commercial and economic development prospects. Connecting wind generators to the distribution network is an important way of utilizing wind power generation. However, numerous wind generators accessed into distribution network will cause great influence on distribution network, whose power quality, active power loss, and reactive power distribution may be changed. Therefore, calculating the power flow of distribution network with wind generators and analyzing the reactive power optimization program are significant for reducing active power loss, improving voltage level, and enhancing effectiveness and stability of power system operation. This paper studies related issues of distribution network with wind generators. Chief research contents are listed as follows.(1) In order to calculate the power flow of distribution network with wind generators, this paper introduces the back/forward sweep algorithm, power characteristic, mathematical models of asynchronous wind generator, and then, the buses voltage and active power loss in network are computed. The results show that the node voltage and active power loss of this system have been effectively improved.(2) Considering the differential evolution algorithm’s drawback in choosing control parameters and falling into the local optimum easily, an improved algorithm is proposed in the dissertation by combining the immune principle and second mutation. Several classic Benchmarks functions and IEEE30buses system are carried out to illustrate the performance of the proposed algorithm.(3) The proposed differential evolution algorithm is adopted to the reactive power optimization problem of distribution network. How to solve the randomness characteristics of wind power is the key of reactive power optimization problem. To deal with it, an uncertain active power is replaced by some certain scenes based on citing scenario analysis. At the same time, in different scenes, this paper establishes a single objective reactive power optimization model mainly containing active power loss, and achieves an optimization scheme of compensation device. In addition, applying one optimization scheme to other scenes, the simulation results indicate that an optimal solution for a specific scene is not necessarily suitable for other scenes, and the all scene is an overall optimal program which can coordinate different scenes.(4) Finally, in the all scene, the proposed algorithm is also applied to a multi-objective reactive power optimization model including active power loss, static voltage stability, and the achievements can be used to provide some optimum proposals. The examples’ analysis in the33-bus distribution network with wind generators verifies the feasibility and effectiveness of the improved algorithm in solving single and multi-objective optimization problems through analyzing contrastively with several algorithms.
Keywords/Search Tags:Distribution network, Wind generator, Back/forward sweep algorithm, Improveddifferential evolution algorithm, Scenario analysis, Multi-objective reactivepower optimization
PDF Full Text Request
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