基于电流正负反馈环效应的弱电网下并网逆变器稳定性分析  

Stability Analysis of Grid-connected Inverter Based on Current Positive and Negative Feedback Loop Effects Under Weak Grid

作　　者：岳菁鹏 安然然 高家元 赵伟 黄振琳 陶然 杨跃 邹凯星 YUE Jingpeng;AN Ranran;GAO Jiayuan;ZHAO Wei;HUANG Zhenlin;TAO Ran;YANG Yue;ZOU Kaixing(Electric Power Research Institute of Guangdong Power Grid Co.,Ltd.,Guangzhou 510080,Guangdong Province,China;National Electric Power Conversion and Control Engineering Technology Research Center(Hunan University),Changsha 410082,Hunan Province,China)

机构地区：[1]广东电网有限责任公司电力科学研究院,广东省广州市510080 [2]国家电能变换与控制工程技术研究中心(湖南大学),湖南省长沙市410082

出　　处：《电网技术》2023年第6期2423-2432,共10页Power System Technology

基　　金：中国南方电网公司科技项目(GDKJXM20212013)。

摘　　要：弱电网下直流母线电压外环及电流内环控制给并网逆变器(grid-connected inverters,GCIs)带来的稳定性问题已被广泛关注,然而电压外环和电流内环控制器参数对GCI稳定性影响存在差异性的现象及其机理却尚未得到直观解析。为此,通过构建考虑直流母线电压动态的GCI小信号数学模型,并通过一系列控制框图等效变换,直观揭示了弱电网下电流内环控制器会经过电网阻抗及锁相环在直流母线电压控制环中形成正负反馈环效应的内在机理。同时,基于GCI的阻抗模型以及控制环路中存在的正负反馈环效应,解析了电压外环与电流内环控制器参数变化对GCI稳定性的影响特性。在此分析基础上,指出GCI稳定性对电流内环控制器参数变化更加敏感;而动态调节特性则对电压外环控制器参数变化更加敏感。最后,通过仿真和实验验证了理论分析的正确性。The stability problem brought by the DC bus voltage outer loop and the current inner loop control to the grid-connected inverter(GCI)system under a weak grid has been widely studied.However,the differences in the influence of the voltage outer loop and the current inner loop controller parameters on the stability of the GCI have not been intuitively analyzed.For this reason,by constructing a GCI small-signal control block diagram that considers the DC bus voltage dynamics,this paper intuitively reveals the inner mechanism of the effect that the current inner loop controller forms a positive and negative feedback loop in the DC bus voltage control loop through the grid impedance and the phase-locked loop in a weak grid.At the same time,based on the GCI impedance model and the positive and negative feedback loop effects in the control loop,the influence characteristics of the voltage outer loop and the current inner loop controller parameter changes on the stability of the GCI are analyzed.It is pointed out that the stability of the GCI is more sensitive to the changes in the parameters of the current inner loop controller,while the dynamic regulation characteristics are more sensitive to the changes in the parameters of the voltage outer loop controller.Finally,the correctness of the theoretical analysis in this paper is verified by simulation and experiment.

关 键 词：弱电网 并网逆变器 小信号模型 正负反馈环效应 稳定性 

分 类 号：TM721[电气工程—电力系统及自动化]