提高并网逆变器在弱电网下鲁棒稳定性的改进电压前馈方法  

Improved voltage feedforward method for improving robust stability of grid-connected inverters in weak grids

作　　者：陈博[1] 曾成碧[1] 苗虹[1] 常宏 CHEN Bo;ZENG Chengbi;MIAO Hong;CHANG Hong(College of Electrical Engineering,Sichuan University,Chengdu 610000,China;China Yangtze Electric Power Co.,Ltd.,Yichang 443000,China)

机构地区：[1]四川大学电气工程学院,四川成都610000 [2]中国长江电力股份有限公司,湖北宜昌443000

出　　处：《电力科学与技术学报》2021年第3期118-124,共7页Journal of Electric Power Science And Technology

基　　金：四川省科技厅项目(2018GZ0394);成都市科技局项目(2017-RK00-00219-ZF)。

摘　　要：由于弱电网中电网阻抗的存在,采用电压前馈控制会对逆变器系统的稳定性产生不利影响。为保留电压前馈控制的优点,首先根据阻抗稳定性分析的方法,分析弱电网中电网阻抗变化时采用电压前馈控制出现的问题,并指出失稳原因和不稳定区域。其次,提出相位超前补偿的方法,增大逆变器输出阻抗的相角,减小由电压前馈控制引起的不稳定区域,保证当电网阻抗变化时,该系统仍具有较强的鲁棒性。最后在Matlab/Simulink进行仿真,仿真结果验证该方法的有效性和可行性。Due to the existence of grid impedance in a weak grid, the application of voltage feedforward control can adversely affect the stability of the inverter system. In order to preserve the advantages of voltage feedforward control, according to the impedance stability analysis method, the problems in adopting voltage feedforward control under grid impedance variation in weak grids are studied. Instability mechanism and unstable region are also presented. Based on the analysis, a phase lead compensation method is proposed to reduce the unstable region caused by voltage feedforward control, increase the phase angle of the inverter output impedance, and safeguard strong robustness to the system when the grid impedance varies. Finally, the simulation experiment is tested in Matlab/Simulink. Simulation results verify the effectiveness and feasibility of the proposed method.

关 键 词：并网逆变器 弱电网 电网阻抗 电压前馈控制 相位超前补偿 

分 类 号：TM46[电气工程—电器]