| 引用本文: | 孙千宸,吴超,王勇,田杰,詹长江.线路阻抗对构网变流器降阶模型精度影响及次同步振荡分析[J].电力自动化设备,2024,44(6):169-175. |
| SUN Qianchen,WU Chao,WANG Yong,TIAN Jie,ZHAN Changjiang.Influence of line impedance on accuracy of reduced-order model for grid-forming converter and sub-synchronous oscillation analysis[J].Electric Power Automation Equipment,2024,44(6):169-175. |
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| 摘要: |
| 在大部分关于构网变流器(GFM)次同步振荡稳定性的研究中，GFM通常被简化为只含有功率外环的三阶模型，这种降阶方法虽然简便，但其精确度会受到线路阻抗特征的影响，因此需要对GFM降阶模型适用性问题展开讨论，并提出更加精准的降阶模型。分析电网线路阻抗特征变化对降阶模型精度的影响，结果表明线路阻感比变化或短路比变化时三阶模型不能精确反映系统特性的变化，会对系统稳定性产生错误判断，其原因在于线路阻抗参数会影响电压环与功率环的耦合特性，2个控制环路均会对GFM次同步振荡稳定性产生影响。提出一种更加准确的包含电压环的降阶模型，可以精确表征线路阻抗特征变化对系统特性的影响，更加适合复杂电网下GFM的稳定性分析。基于MATLAB/Simulink仿真验证了理论分析的正确性及所提模型的有效性。 |
| 关键词: 构网变流器 小信号模型 参与因子分析 线路阻抗 次同步振荡 |
| DOI：10.16081/j.epae.202311020 |
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| Influence of line impedance on accuracy of reduced-order model for grid-forming converter and sub-synchronous oscillation analysis |
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SUN Qianchen1, WU Chao1, WANG Yong1, TIAN Jie2, ZHAN Changjiang2
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1.School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200241, China;2.Nanjing NR Electric Co.,Ltd.,Nanjing 211102, China
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| Abstract: |
| In most studies on the sub-synchronization oscillation stability of grid-forming converter(GFM),GFM is usually simplified to a three-order model only containing the power outer loop. Although this method is simple, its accuracy will be affected by the characteristics of line impedance. Therefore, it is need to discuss the applicability of reduced-order model for GFM and propose a more accurate reduced-order model. The influence of the variation of characteristics of line impedance on the accuracy of reduced-order model is analyzed, and the results show that the third-order model cannot accurately reflect the variation of system characteristics when the line resistance ratio or short circuit ratio(SCR) changes, and it will make wrong judgment on the system stability. The reason is that the impedance parameters of the line will affect the coupling characteristics of the voltage loop and the power loop, and both control loops will affect the stability of GFM sub-synchronization oscillation. A more accurate reduced-order model including voltage loop is proposed, which can accurately represent the influence of the variation of characteristics of line impe-dance on system characteristics, and is more suitable for the stability analysis of GFM under complex power grid. The correctness of the theoretical analysis and the effectiveness of the proposed model are verified based on MATLAB/Simulink simulation. |
| Key words: grid-forming converter small-signal model participation factor analysis line impedance sub-synchronous oscillation |
