分数阶插入式前馈重复控制及单相并网逆变器应用

Fractional-order plug-in feedforward repetitive control and its application to single-phase grid-tied inverters

中文关键词  分数阶延迟  重复控制  Farrow结构滤波器  谐波抑制  频率波动

英文关键词  fractional-order delay  repetitive control  Farrow structure filter  harmonics suppression  frequency fluctuation

中文摘要

      针对传统插入式重复控制器(PRC)在弱电网频率波动时控制性能下降的问题, 本文提出一种基于Farrow结 构滤波器的分数阶插入式前馈重复控制(FOPFRC) 方法. 首先, 采用前馈重复控制内模结构优化PRC的内模, 改善 系统应对电网频率波动的鲁棒性; 其次, 采用Farrow 结构滤波器实时逼近由电网频率波动导致的分数阶延迟, 使前 馈重复控制的谐振频率实时跟踪电网频率, 进一步改善控制系统在电网频率波动时的谐波抑制性能; 最后, 给出了 FOPFRC 系统的稳定性分析和控制器参数优化设计方法. 实验结果证明, 提出的 FOPFRC 方法在电网电压畸变、电 网频率波动以及电网电压突变等弱电网工况下具有较强的谐波抑制能力和较好的动态性能.

英文摘要

      In order to address the problem that the control performance of the conventional plug-in repetitive controller (PRC) is degraded when the weak grid frequency fluctuates, a fractional-order plug-in feedforward repetitive control (FOPFRC) method based on the Farrow structure filter is proposed in this paper. Firstly, the feedforward repetitive control internal model structure is introduced to optimize the internal model of the PRC, which improves the robustness of the system against the grid frequency fluctuations. Secondly, the Farrow structure filter is used to approximate simultaneously the fractional-order delay caused by the grid frequency fluctuations, so that the resonant frequency of the feedforward repetitive control can track the grid frequency in real time, further improving the harmonics suppression performance of the control system when the grid frequency fluctuates. Finally, the stability analysis and controller parameters optimization design method of the FOPFRC system are given. The experimental results show that the proposed FOPFRC method has strong harmonics suppression capability and good dynamic performance under weak grid conditions such as grid voltage distortion, grid frequency fluctuations, and grid voltage dips.