Impedance modeling of three-phase grid-connected inverters and analysis of interaction stability in grid-connected system
Impedance modeling of three-phase grid-connected inverters and analysis of interaction stability in grid-connected system
复制标题
DOI：
10.1109/ipemc.2016.7512873
复制
发表时间：
2016-05
期刊：
影响因子：
--
通讯作者：
Yuncheng Wang;Xin Chen;Yang Zhang;Jie Chen-;Chunying Gong
中科院分区：
文献类型：
--
作者：
Yuncheng Wang;Xin Chen;Yang Zhang;Jie Chen-;Chunying Gong
在分布式发电系统中，并网逆变器的稳定性直接关系到并网系统的可靠运行。基于阻抗的分析方法可以有效地研究并网逆变器与电网之间的相互作用稳定性，这意味着需要获得并网逆变器的阻抗模型以进行阻抗稳定性分析。以三相LCL型并网逆变器为研究对象，采用谐波线性化方法分析了锁相环的频率特性，提出了锁相环调节器参数的设计方法。同时，考虑锁相环和数字控制延时等因素对阻抗特性的影响，结合谐波线性化和对称分量法建立了并网逆变器的正序和负序阻抗模型。仿真结果验证了锁相环的频率特性，实验结果验证了并网逆变器的输出阻抗模型，有效地证明了理论分析的正确性。最后，基于并网逆变器的输出阻抗模型，采用基于阻抗的分析方法对并网系统的互作用稳定性进行了理论分析和实验验证。
In a distributed generation system, the stability of grid-connected inverters is directly related to the reliable operation of the grid-connected system. The impedance-based analysis method can be employed to effectively study the interaction stability between grid-connected inverters and grid, which means that it is necessary to obtain the impedance modeling of grid-connected inverters for the analysis of impedance stability. Based on the three-phase LCL-type grid-connected inverter, the harmonic linearization method was adopted in this paper to analyze the frequency characteristic of Phase-Locked Loop (PLL), and a design approach of PLL regulator parameters was proposed. Meanwhile, the impacts of the factors that include PLL and digital control delay on the impedance characteristic were considered, and the positive-sequence and negative-sequence impedance model of the grid-connected inverter was built by combining the harmonic linearization and symmetrical component methods. Then, the frequency characteristic of PLL was verified by the simulation results and the output impedance model of the grid-connected inverter was verified by the experimental results, which effectively proved the correctness of the theoretical analysis. Finally, based on the output impedance model of the grid-connected inverter, the impedance-based analysis method was adopted to make a theoretical analysis and experiment validation of the interaction stability of the grid-connected system.