提高光伏并网逆变器在弱电网下稳定性的阻抗相角补偿控制  

Impedance phase angle compensation control for improving stability of photovoltaic grid-connected inverter in weak grid

作　　者：高选杰 苗虹[1] 曾成碧[1] 熊正勇 Gao Xuanjie;Miao Hong;Zeng Chengbi;Xiong Zhengyong(School of Electrical Engineering and Information Technology,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学电气信息学院

出　　处：《电测与仪表》2019年第22期1-6,共6页Electrical Measurement & Instrumentation

基　　金：四川省科技厅资助项目(2018GZ0394)

摘　　要：针对LCL型并网逆变器自身存在的谐振现象,提出一种电容电压惯性反馈控制策略,来抑制其谐振尖峰。在弱电网状况下,由于电网阻抗和并网逆变器输出阻抗的相互作用,使得并网逆变器的稳定性急剧恶化。于是提出输出阻抗相角补偿加滤波器的方法,提高逆变器输出阻抗相角使其满足稳定裕度,从而提高并网逆变器在弱电网下的稳定性。在MATLAB/Simulink仿真平台上搭建并网逆变器系统仿真模型,对所提方法进行仿真验证。仿真结果表明,所提方法不仅能提高并网逆变器的稳定性,而且能改善并网电流的质量,降低谐波总畸变率。Aiming at the resonance phenomenon of grid-connected inverter with LCL,an inertial feedback control strategy based on capacitor voltage is proposed to suppress the resonance peak.However,in the case of weak grid,the stability of grid-connected inverter deteriorates sharply due to the interaction between the grid impedance and the output impedance of grid-connected inverter.Therefore,a phase angle compensation method with filter is proposed to improve the output impedance phase angle of the inverter to meet the stability margin,thus improving the stability of grid-connected inverter in weak grid.The simulation model of grid-connected inverter system is built on MATLAB/Simulink platform and the proposed method is verified by simulation.The simulation results show that the proposed method cannot improve the stability of grid-connected inverter,but also improve the quality of grid-connected current and reduce the total harmonic distortion rate(THD).

关 键 词：并网逆变器 弱电网 惯性反馈 相角补偿 相角裕度 谐波总畸变率 

分 类 号：TM615[电气工程—电力系统及自动化]