弱电网下计及直流母线和镜像频率耦合扰动的三相LCL型并网逆变器序导纳建模及稳定性分析  

Sequence admittance modeling and stability analysis for three-phase LCL-typegrid-connected inverter with DC bus and MFC disturbance under weak grid

作　　者：朱益良 蒲俊楷 葛兴来[1] 闫培雷 孙伟鑫 李婷婷 刘川 ZHU Yiliang;PU Junkai;GE Xinglai;YAN Peilei;SUN Weixin;LI Tingting;LIU Chuan(Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle,Southwest Jiaotong University,Chengdu 610031,China;Chengdu Yunda Technology Co.,Ltd.,Chengdu 610097,China)

机构地区：[1]西南交通大学磁浮技术与磁浮列车教育部重点实验室,四川成都610031 [2]成都运达科技股份有限公司,四川成都610097

出　　处：《电力自动化设备》2020年第9期190-196,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51677156,61733015)。

摘　　要：为解决新能源并网系统的交互失稳问题,首先运用双谐波线性化方法,综合考虑直流母线与镜像频率耦合扰动,建立三相LCL型并网逆变器的序导纳模型;进一步将传统的矩阵序导纳模型简化为单输入单输出序导纳模型,分别分析锁相环、直流电压外环和电流内环控制器的带宽对并网逆变器导纳特性的影响规律;最后基于MATLAB/Simulink仿真平台,验证了非线性时域系统中所建序导纳模型的准确性,并通过奈奎斯特稳定判据证明了所提模型可有效地提高弱电网下并网交互系统稳定性。In order to solve the interaction instability of new energy grid connection system,firstly,the sequence admittance model of three-phase LCL-type grid-connected inverter is established by using the doubleharmonic linearization method and comprehensively considering the DC bus and the MFC(Mirror Frequency Coupling)disturbance.Furthermore,the traditional matrix sequence admittance model is simplified to a sin⁃gle-input single-output sequence admittance model.The influence law of the controller bandwidth of the phase locked loop,the DC voltage outer loop and the current inner loop on the admittance characteristics of the grid-connected inverter is analyzed separately.Finally,based on the MATLAB/Simulink platform,the accuracy of the proposed sequence admittance model in nonlinear time-domain system is verified,and it is proved by Nyquist stability criterion that the proposed model can effectively improve the stability of interconnected system under weak grid.

关 键 词：弱电网 并网逆变器 镜像频率耦合 稳定性分析 双谐波线性化 

分 类 号：TM712[电气工程—电力系统及自动化] TM464