弱电网下LCL型逆变器的改进并网电流控制策略  

Improved Grid-connected Current Control Strategy for LCL-type Inverter Connected to Weak Grid

作　　者：朱胤杰 苗虹[1] 曾成碧[1] 童广 ZHU Yinjie;MIAO Hong;ZENG Chengbi;TONG Guang(School of Electrical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学电气工程学院,成都610065

出　　处：《电源学报》2024年第6期81-90,共10页Journal of Power Supply

基　　金：国家重点研发计划资助项目(2018YFC1505502-03);四川省重点研发资助项目(2021YFG0256,2021YFG0218)。

摘　　要：针对弱电网环境下电网阻抗的出现导致LCL型并网逆变器系统的相位裕度下降,造成严重的并网电流畸变,甚至系统失稳的问题,提出1种改进并网电流控制策略。在电压前馈环中引入多谐振控制器以抑制电网电压背景谐波,并在电流前馈环中加入相位补偿器以提升系统相位裕度,从而避免多谐振环节的谐振峰与−180°线交汇的风险。理论分析与仿真实验结果均表明,所提策略可有效抑制弱电网下LCL型并网电流谐波,提高电流质量,增强并网系统的稳定性。For an LCL-type inverter connected to weak grid,the appearance of grid impedance often results in a decrease in the phase margin,serious distortion of grid-connected current and even system instability.To solve this problem,an improved grid-connected current control strategy is proposed,in which a multi-resonance controller is introduced in the voltage feedforward loop to suppress the voltage background harmonics and a phase compensator is added to the current feedforward loop to improve the system’s phase margin,so as to avoid the risk that the resonance peak of the multi-resonance link intersects with the–180°line.Theoretical analysis and simulation results show that the proposed strategy can effectively suppress the harmonics of LCL-type grid-connected current,improve the current quality and enhance the stability of the grid-connected system.

关 键 词：弱电网 LCL型并网逆变器 多谐振控制器 并网电流前馈 相位补偿器 

分 类 号：TM464[电气工程—电器]