| 引用本文: | 谢佳骏,邹志翔,薛明军,杨黎明,陈琦,刘志仁,王政.不平衡电网下并网逆变器双序功率控制阻抗建模及稳定分析[J].电力自动化设备,2025,45(5):118-127. |
| XIE Jiajun,ZOU Zhixiang,XUE Mingjun,YANG Liming,CHEN Qi,LIU Zhiren,WANG Zheng.Impedance modeling and stability analysis of double sequence power control of grid-connected inverters in unbalanced power grid[J].Electric Power Automation Equipment,2025,45(5):118-127. |
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| 摘要: |
| 选取带双二阶广义积分器锁相环的并网逆变器为研究对象，分析不平衡电网下的双序电流控制和外加功率环(对称正序控制、正序负序控制、平均有功-无功控制)的控制方法，并探究双序相角下的频率耦合现象。在利用谐波线性化方法完成锁相环、电流环与功率外环的小信号分析后，推导出并网逆变器双序导纳模型。利用广义奈奎斯特稳定性判据，借助特征根灵敏度分析法横向比较了3种功率控制方法在不平衡电网下的稳定性，并纵向对比了有无功率外环控制的系统变化。通过建立系统参数变化与判稳矩阵在关键频段特征根幅相特性的映射关系，可以为系统稳定性设计提供理论指导。通过硬件在环实时仿真平台完成验证，结果表明：采用正序负序控制相较另2种功率控制方式存在更高的失稳风险；对要求纯正序电流并网的工况，添加功率外环控制可有效提升系统稳定性。 |
| 关键词: 不平衡电网 并网逆变器 双序控制 功率控制 阻抗建模 稳定性分析 硬件在环 |
| DOI：10.16081/j.epae.202504002 |
| 分类号:TM464 |
| 基金项目:国家自然科学基金资助项目(52377171)；中央高校基本科研业务费专项资金资助项目(2242024K40030) |
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| Impedance modeling and stability analysis of double sequence power control of grid-connected inverters in unbalanced power grid |
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XIE Jiajun1, ZOU Zhixiang1, XUE Mingjun2, YANG Liming2, CHEN Qi2, LIU Zhiren3, WANG Zheng1
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1.School of Electrical Engineering, Southeast University, Nanjing 210096, China;2.Guodian Nanjing Automation Co.,Ltd.,Nanjing 210032, China;3.State Grid Wuxi Power Supply Company, Wuxi 214000, China
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| Abstract: |
| Taking the grid-connected inverters with double second-order generalized integrator phase locked loop(DSOGI-PLL) as the research object, the control methods of double sequence current control and external power loop, such as balanced positive-sequence control(BPSC),positive-and negative-sequence control(PNSC) and average active-reactive control(AARC),under unbalanced grid conditions are analyzed, and the frequency coupling phenomenon under double sequence phase angle is explored. After the small-signal analysis of the phase locked loop, current loop and power outer loop using harmonic linearization method, the double sequence admittance models for grid-connected inverters are derived. By applying generalized Nyquist criterion and the eigenvalue sensitivity analysis, the stability of three power control methods under unbalanced power grid is compared, as well as the system characteristics are compared between with and without power outer loop. The relationship between the variation of system parameters and the amplitude and phase characteristics of characteristic roots of stability judgment matrix in critical frequency bands is thus established to provide theoretical guidance for system stability design. Verification is completed through the hardware-in-the-loop platform. The results show that the PNSC has a higher risk of instability compared with other two methods, and adding power outer loop control can effectively enhance the stability of the system under the working conditions that require pure positive-sequence current injection. |
| Key words: unbalanced power grid grid-connected inverter double sequence control power control impedance modeling stability analysis hardware-in-the-loop |
