摘要
针对弱电网下并网逆变器不同功率因数下的运行特性及稳定性问题问题,从阻尼比的角度入手,分别在相同参数条件下构建dq坐标系下基于锁相环(PLL)的电流环、电压电流双环矢量控制以及虚拟同步发电机(VSG)控制的并网逆变器小信号模型并绘制其阻尼比特性曲线图。发现d、q轴环路在强弱电网下呈现的稳定性并不相同,即弱电网下存在“dq轴不对称”现象。通过对比分析发现,当功率因数角在-90°~0°~90°变化时,并网角度的参与因子在PLL型控制方式下先增大后减小,在VSG控制下则反之;此外,双环矢量控制策略dq环路稳定性的不对称性尤为明显,参与变量较多,部分功率因数下电流环d、q轴2个积分环节对同一振荡的参与度差异较大,不稳定范围变宽。最后,基于Simulink仿真软件和远宽半实物平台验证该文理论研究的正确性。
Onder the weak cuvrent network,grid-cornnected inverters need both altive and power to support operation simultaneously.so its operating characteristic and stability issue under different power factors are particularly important.Therefore,from the perspective of system damping ratio,the small signal models of grid-connected inverter under three control methods are respectively constructed:current loop vector control based on phase-locked loop(PLL),voltage and current double loop vector control and virtual synchronous generator(VSG)control under d-q synchronous rotating reference frame.It is found that when the current vector is a circular trajectory,its damping ratio characteristic is a non-circular trajectory.It means d-q axis present different stability feature,namely stability‘asymmetry’phenomenon;Based on that,it is found that the integral term,PLL and VSG angle under the three control methods have the greatest impact on the symmetry of the power stability.Besides,when power factor changes from-90°~0°~90°,the participation factor of the PLL angle increases first and then decreases,and vice versa for VSG angle.In addition,the oscillation modes related to the‘asymmetrical’characteristics is more under the double-loop vector control strategy and the participation of the two integral links of the current loop d and q axes on the same oscillation mode is quite different;the range of instability is wider and the phenomenon of‘asymmetry’is more obvious.Finally,the accuracy of the analysis is verified by Matlab simulation and experimental platform.
作者
郝木凯
王伟胜
刘芳
袁耿涛
李学先
Hao Mukai;Wang Weisheng;Liu Fang;Yuan Gengtao;Li Xuexian(School of Electric and Electronic Engineering,North China Electric Power University,Beijing 100085,China;Industry Development and Promotion Center,Ministry of Industry and Information Technology,Beijing 100085,China;China Electric Power Research Institute Co.,Ltd,Beijing 100085,China;School of Electric Engineering and Automation,Hefei University of Technology,Hefei 230009,China)
出处
《太阳能学报》
北大核心
2025年第8期612-624,共13页
Acta Energiae Solaris Sinica
关键词
阻尼比
并网逆变器
dq轴不对称自同步
弱电网
电压电流双环矢量控制
参与因子
damping ratio
grid-connected inverter
d-q axis asymmetric self-synchronization
weak grid
voltage and current dualloop vector control
participation factor
作者简介
通信作者:刘芳(1980-),女,博士、副教授,主要从事新能源并网发电技术等方面的研究。fragcelau@hfut.edu.cn。
