弱电网下基于功率前馈的光伏并网逆变器稳定性分析  

Stability analysis of grid-connected photovoltaic inverter based on power feedforward under weak grid condition

作　　者：刘鑫蕊[1] 孙浩楠 曹传超 孙秋野[1] LIU Xin-rui;SUN Hao-nan;CAO Chuan-chao;SUN Qiu-ye(College of Information Science and Engineering,Northeastern University,Shenyang 110004,China)

机构地区：[1]东北大学信息科学与工程学院,沈阳110004

出　　处：《控制与决策》2022年第4期989-996,共8页Control and Decision

基　　金：国家重点研发计划项目(2018YFA0702200);中央高校基本科研业务费专项资金项目(N2004013)。

摘　　要：光伏并网逆变器的直流侧电压在光照强度、温度等外界环境的影响下通常是波动的,这会对弱电网下光伏并网系统的稳定性产生影响.针对这一问题,在传统控制系统中引入基于功率前馈的电压控制回路,并给出其结构和参数的设计过程.在此基础上,对光伏并网逆变器的输出阻抗进行建模,并分析不同控制器下对应的输出阻抗的频率特性,并利用奈奎斯特稳定性判据,分析弱电网下光伏并网系统的稳定性.最后,通过仿真实验验证所提出控制策略的有效性.DC side voltage of grid-connected photovoltaic inverters usually fluctuates under the influence of the external environment such as light intensity and temperature,which will affect the stability of grid-connected photovoltaic systems under the weak current network.To solve this problem,a voltage control loop based on power feedforward is introduced into the traditional control systems,and the design process of its structure and parameters is given.On this basis,the output impedance of the grid-connected photovoltaic inverter is modeled,and the frequency characteristics of the corresponding output impedance under different controllers are analyzed.The stability of the grid-connected photovoltaic system under weak current is analyzed using the Nyquist stability criterion.Finally,the effectiveness of the proposed control strategy is verified by simulation.

关 键 词：光伏并网逆变器 功率前馈 阻抗分析法 频率特性 弱电网 稳定性分析 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]