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

作　　者：杜燕[1,2] 言明明[1,2] 杨向真 张梦梦[1,2] 孙青青 苏建徽 DU Yan;YAN Ming-ming;YANG Xiang-zhen;ZHANG Meng-meng;SUN Qing-qing;SU Jian-hui(School of Electrical Engineering and Automation,Hefei University of Technology,Hefei Anhui 230009,China;Research Center for Photovoltaic Systems Engineering of Ministry of Education,Hefei Anhui 230009,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,安徽合肥230009 [2]教育部光伏系统工程研究中心,安徽合肥230009

出　　处：《控制理论与应用》2022年第4期701-710,共10页Control Theory & Applications

基　　金：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。

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.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.

关 键 词：并网逆变器 弱电网 锁相环 稳定性 阻抗重塑 

分 类 号：TM464[电气工程—电器]