融合改进重复控制–分数阶自抗扰的LCL型并网逆变器电流控制(英文)

Current control of LCL grid-connected inverter with improved repeated control-fractional order linear active disturbance rejection

中文关键词  LCL型逆变器  改进重复控制  分数阶自抗扰控制  电流谐波抑制

英文关键词  LCL inverter  improved repetitive control  fractional order active disturbance rejection control  current harmonic suppression

中文摘要

      三相LCL型逆变器具有高频抑制明显和体积较小的优点, 但LCL型滤波器固有谐振峰易导致系统不稳定. 本文 设计了基于分数阶线性扩张状态观测器(FOLESO)的分数阶自抗扰控制(FOLADRC)策略, 利用FOLESO的扰动补偿特 性有效地抑制了系统的谐振峰. 在此基础上, 引入了具有无相移低通滤波器和降阶型频率自适应相位滞后环节的改进重 复控制(RC)策略, 进一步提高系统对周期性电流谐波抑制能力. 本文还给出了改进重复控制–分数阶自抗扰控制(RCFOLADRC)策略的详细设计过程、参数选择方法和相关性能分析. 仿真和实验结果表明, 所提出RC-FOLADRC在保证 电流跟踪性能的基础上, 对电网阻抗变化、LCL滤波器参数变化和电网频率波动有很强的鲁棒性, 能够有效地应用 于LCL型逆变器并获得较为理想的并网电流.

英文摘要

      A three-phase LCL inverter has the advantages of significant high-frequency suppression and compact size. However, the inherent resonance of the LCL filter can easily lead to system instability. In this paper, a fractional order linear active disturbance rejection control (FOLADRC) based on fractional order linear expansion state observer (FOLESO) is designed. The disturbance compensation characteristics of FOLESO are used to suppress system resonance. On this basis, an improved repetitive control (RC) with a phase-shift-free low-pass filter and a reduced-order frequency-adaptive phase lag link is introduced to further enhance the system’s capability to suppress periodic current harmonics. The detailed design process, parameter tuning, and related performance analysis of the improved repeated control – fractional order linear active disturbance rejection control (RC-FOLADRC) strategy are provided. Simulation and experimental results demonstrate that the proposed RC-FOLADRC exhibits strong robustness to disturbances in grid impedance, LCL filter parameters, and grid frequency, while ensuring accurate current tracking performance. Therefore, the RC-FOLADRC can be effectively applied to LCL inverters, resulting in optimal grid-connected current.