多光伏发电单元并联接入弱电网时的运行控制策略研究

项目名称： 多光伏发电单元并联接入弱电网时的运行控制策略研究

项目编号： No.51277024

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 电工技术

项目作者： 严干贵

作者单位： 东北电力大学

项目金额： 80万元

中文摘要： 大规模联网型光伏电站通常采用经逆变器并网的多光伏发电单元并联结构。受资源禀赋约束，大规模光伏电站多位于电网结构薄弱的沙漠/半沙漠地带。随着光伏发电系统并网容量的增加，光伏发电系统的等值阻抗减小，当其等值阻抗降至与弱电网等值阻抗相比不可忽视时，光伏电站的发电功率波动将严重影响并网点的电压质量，进而影响光伏逆变器的并联运行性能，甚至可能导致多光伏发电单元并联运行的不稳定。本申报书拟针对"多光伏发电单元并联接入弱电网时的运行控制策略设计"问题，深入研究4个科学问题：1）既有控制策略下光伏逆变器功率-电压动态特性；2）连接波动特性各异光伏电源时多光伏逆变器并联运行的耦合机理；3）接近电网输电瓶颈工况时多光伏逆变器并联接入弱电网运行稳定性分析；4）多光伏逆变器并联接入弱电网时的运行控制策略设计及效益评估。为提高大规模光伏电站并联接入弱电网时运行的稳定性提供理论指导，促进太阳能的大规模开发利用。

中文关键词： 光伏发电；弱电网；稳定性分析；阻抗模型；状态空间模型

英文摘要： As the energy density of photovoltaic panels is relatively low，the large-scale grid-connected PV stations usually adopt multiple parallelled-inverter for multiple photovoltaic generation units connected to the grid. Due to the restriction of resource endowment, large scale photovoltaic power stations are mostly located in deserts/semideserts where the grid structure is relatively weak.With the increasing capacity of grid-connected photovoltaic power generation,the equivalent impedance of photovoltaic generation system is gradually reducing. When the equivalent impedance reduce to the value that can not be ignored compared with the weak grid impedance, the generation power fluctuation of photovoltaic power station will seriously affect the voltage quality of the public connection point(PCC) to the grid, and then influence the operation performance of paralleled-inverters, and even may lead to the operation instability of parallelled-inverters for multiple photovoltaic generation units. This proposal is aimed to the problem "Study on the control strategy of multiple paralleled-inverters for photovoltaic generation units connected to the weak grid", and to study the following four problems: 1)the power-voltage dynamic regulation performance of an inverter for photovoltaic generation governed by the maximum power p

英文关键词： PV generation；weak grid；stability analysis；impedance model；state space model