多目标约束下逆变器阻抗的电流矫正方法
Current correction method for grid-connected inverter impedance under multi-objective constraints
摘要点击 107  全文点击 26  投稿时间:2020-12-14  修订日期:2021-06-28
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DOI编号  10.7641/CTA.2021.00897
  2022,39(4):701-710
中文关键词  并网逆变器  弱电网  锁相环  稳定性  阻抗重塑
英文关键词  grid-connected inverter  weak grid  phase-locked loop  stability  impedance reshaping
基金项目  国家重点研发计划项目(2018YFB0904102), 高等学校学科创新引智计划(111计划)(BP0719039)资助.
作者单位E-mail
杜燕 合肥工业大学电气与自动化工程学院 dydf@sina.com 
言明明 合肥工业大学电气与自动化工程学院  
杨向真 合肥工业大学电气与自动化工程学院 yxz_greenleaf@163.com 
张梦梦 合肥工业大学电气与自动化工程学院  
孙青青 合肥工业大学电气与自动化工程学院  
苏建徽 合肥工业大学电气与自动化工程学院  
中文摘要
      弱电网下锁相环与电网阻抗间的耦合会造成系统不稳定. 含前置低通滤波器锁相环的并网逆变器虽能改 善并网系统稳定性, 但存在并网电流相位滞后问题. 本文通过将滤波器从锁相环支路“拆分”, 提出了一种电流二 阶校正的阻抗重塑法, 以基波电流控制性能、相角裕度、低频幅值为约束建立了多目标约束函数, 单独优化设计了 二阶校正环节参数, 提高了并网逆变器的弱网稳定性, 实现弱电网下的单位功率因数并网. 最后在StarSim实验平台 验证了所提控制方法的有效性.
英文摘要
      Under a weak grid, the system instability can be jeopardized by the interaction between the phase-locked loop and the grid impedance with increasing impedance. Although the stability of grid-connected system can be improved by a phase-locked loop with a serial low-pass filter (LPF), it leads to a lag phase of injected grid current. Based on the equivalent transformation and frequency division optimization, an impedance reshaping method with second-order correction of the current is proposed. Then a multi-objective constraint function is established with the constraints of base-wave current control performance, phase angle margin, and low-frequency amplitude. And the parameters of the second-order correction link are optimally designed by this function. The method improves the weak grid stability of the grid-connected inverter and realizes the grid connection with unit power factor under the weak grid. Finally, the effectiveness of the proposed control method was verified on the StarSim experimental platform.