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Research On Small Signal Stability Of Island Microgrid Based On Photovoltaic Power Generations

Posted on:2018-07-16Degree:MasterType:Thesis
Country:ChinaCandidate:N J DengFull Text:PDF
GTID:2322330518463711Subject:Power system and its automation
Abstract/Summary:PDF Full Text Request
The island has a unique advantage in resources,the full development and utilization of resources on the island gradually become one of the main ways to develop renewable energy sources in the world.The island construction depends on the power supply,electric power is an important premise to protect the island residents daily production and cultural life however,limited by economic conditions,the island power supply of energy transmission lines exist the problem of high cost and long delivery;on the other hand,the island and its surrounding itself has not yet developed and abundant renewable energy.Therefore,it is necessary to build a variety of renewable energy,stable and reliable Island microgrid,energy conservation and environmental protection in order to promote the island's economic development.Solar power generation is very different from traditional generator sets.For example,sunlight is affected by the weather,geographical location and time period and other factors,showing a unique intermittent;Photovoltaic power generation through the inverter interface networking,the regulation of reactive power is weak,etc.This is the fundamental difference between the power characteristics of photovoltaic system and traditional power generation equipment,and in practice the system small interference signal appears anywhere.In order to implement the security,economy and stability of the island microgrid,it is necessary to study the small signal stability of the island microgrid.In this paper,the small signal stability of photovoltaic access One-Machine Infinite Bus(OMIB)system is studied firstly.The mathematical model of the photovoltaic power generation system is established,which consists of PV cell model,control model and inverter model.Then according to the linearized mathematical model,the state matrix is obtained and the eigenvalues,which are used to judge the stability of the system,are computed.After that,the relevance between the characteristic mode and each state variable is analyzed by combining the participation factor,and the appropriate control parameters are designed by the eigenvalue traces.Next,the MATLAB/Simulnk model of photovoltaic power generation system is established.The simulation results verify the correctness and effectiveness of eigenvalue analysis method and the rationality of the design of related parameters.Then,the small signal stability of island microgrid composed of photovoltaic cells,batteries,lines and loads is analyzed.The microgrid model is deduced,and all the components of the network are linearized to build a complete small signal model of microgrid.The eigenvalue is solved by taking the initial value of the stable operation into the state matrix expression.The left and right eigenvectors of the state equation are calculated,and the elements of the participating matrix are obtained by calculation.The mechanism of the characteristic mode generation is studied,and the control parameters which affect the degree of state variables are found.Through the design of.these parameters to optimize the distribution of eigenvalues,so that the system is in a relatively stable state of operation.Finally,the island microgrid model is built in MATLAB/Simulnk simulation software and perform simulation analysis.The simulation results verify the correctness of the theoretical analysis.
Keywords/Search Tags:Island microgrid, Photovoltaic generation, Microgrid, Small signal stability, Eigenvalue analysis
PDF Full Text Request
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