基于无源性的LCL型并网逆变器序导纳模型及高频稳定性研究  

Research on Sequence Admittance Model and High-frequency Stability of LCL-type Grid-connected Inverters Based on Passivity

作　　者：胡雪凯 孟良 高子鹏 肖国春[2] 肖霖涛 HU Xuekai;MENG Liang;GAO Zipeng;XIAO Guochun;XIAO Lintao(State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021,China;Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,河北石家庄050021 [2]西安交通大学,陕西西安710049

出　　处：《河北电力技术》2025年第1期10-19,共10页Hebei Electric Power

基　　金：国网河北省电力有限公司科技项目(kj2023-017)。

摘　　要：LCL型滤波器因其优良的谐波衰减能力在并网逆变器中得到了广泛应用,但其固有的谐振尖峰及非理想电网下并网逆变器与电网阻抗的交互作用可能引发高频振荡等稳定性问题。首先,基于谐波线性化方法,采用电容串联电阻无源阻尼和电容电流反馈有源阻尼,建立了dq坐标系控制的三相LCL型并网逆变器统一序导纳模型。然后,基于所建的序导纳模型和无源性理论分析不同阻尼方式对导纳特性和系统高频稳定性的影响,对最优有源阻尼系数进行设计,并针对单一阻尼方式存在的问题,提出了最优有源阻尼结合无源阻尼的混合阻尼方式,提升了系统在1/6采样频率处的稳定裕度以及对电网阻抗和滤波器参数的鲁棒性。最后,基于MATLAB/Simulink仿真验证了理论的正确性和所提混合阻尼方式的有效性。LCL-type filters are widely used in grid-connected inverters due to their excellent harmonic attenuation capabilities.However, the inherent resonance spikes of LCL-type filters, combined with the interaction between grid-connected inverters and the grid impedance under non-ideal grid, may lead to stability problems, such as high-frequency oscillations.To address this, a unified sequence admittance model of the three-phase LCL-type grid-connected inverter, controlled in the dq-frame with both capacitor series resistance passive damping and capacitor current feedback active damping, is first established based on the harmonic linearization method.Subsequently, based on the established sequence admittance model and passivity theory, the effects of various damping methods on admittance characteristics and system high-frequency stability are analyzed, and the optimal active damping coefficient is also designed.Aiming at the problems of single damping method, a hybrid damping method that combines the optimal active damping with passive damping is proposed, which enhances the stability margin of the grid-connected system at 1/6 of the sampling frequency and improves the robustness to the grid impedance and filter parameters.Finally, simulations based on MATLAB/Simulink validate the theoretical analysis and demonstrate the effectiveness of the proposed hybrid damping method.

关 键 词：并网逆变器 序导纳 无源性 高频稳定性 混合阻尼 

分 类 号：TM464[电气工程—电器]