复杂电网环境下并网逆变器强迫振荡机理分析与抑制  

Mechanism analysis and suppression strategy of forced oscillation for grid-connected inverter under complex power grid conditions

作　　者：王毅 李琼林 刘书铭 林芳 孙建军[3] WANG Yi;LI Qionglin;LIU Shuming;LIN Fang;SUN Jianjun(Electric Power Research Institute of State Grid Henan Electric Power Co.,Ltd.,Zhengzhou 450000,China.;Electric Power Research Institute of State Grid Fujian Electric Power Co.,Ltd.,Fuzhou 350007,China.;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]国网河南省电力有限公司电力科学研究院,郑州450000 [2]国网福建省电力有限公司电力科学研究院,福州350007 [3]武汉大学电气与自动化学院,武汉430072

出　　处：《电测与仪表》2024年第6期51-57,共7页Electrical Measurement & Instrumentation

基　　金：国家自然科学基金资助项目(51777145);国家电网有限公司总部科技项目(5400-201921142A-0-0-00)。

摘　　要：随着现代工业的迅速发展,非线性电力负荷不断增加,电网电压中出现了大量谐波和间谐波,电网环境日益复杂,这对并网逆变器的安全稳定运行提出了新的挑战。文章详细分析了复杂电网环境下由间谐波电压诱发并网逆变器产生振荡的机理,并提出了相应的振荡抑制措施。文中介绍了电网电压中间谐波的特点及其对并网逆变器输出功率的影响,发现间谐波电压会导致逆变器输出有功功率中存在持续性的周期性波动。通过一个保留主导特征值的逆变器降阶模型,从强迫振荡的角度揭示了周期性的功率波动诱发并网逆变器振荡的机理与特点。在此基础上发现强迫振荡的幅值和主导特征值的阻尼强相关,并提出了直流电压控制环时间尺度的有源阻尼来抑制强迫振荡。最后通过仿真验证了文中振荡机理分析的正确性和振荡抑制策略的有效性。The nonlinear power loads are increasing with the rapid development of the modern industry,resulting in a large number of harmonics and inter-harmonics appear in the power grid,and the power grid environment is increasingly complex,which poses a new challenge to the safe and stable operation of grid-connected inverter.In this paper,the mechanism of the grid-connected inverter oscillation induced by inter-harmonic voltage under complex grid conditions is analyzed in detail,and the corresponding oscillation suppression measures are proposed.Firstly,the characteristics of the inter-harmonics in power grid and the influence of the inter-harmonic on the output power of the grid-connected inverter are introduced.It is found that the inter-harmonics will lead to continuous periodic fluctuations in the output active power of the inverter.Then,the mechanism and characteristics of the oscillation induced by periodic power fluctuation are revealed from the perspective of forced oscillation by a reduced-order inverter model with dominant oscillation modes reserved.On this basis,it is found that the amplitude of the forced oscillation is strongly correlated with the damping of the dominant oscillation modes,and then,an active damping in the DC-link voltage control loop is proposed to suppress the forced oscillation.Finally,the correctness of the oscillation mechanism analysis and the effectiveness of the oscillation suppression strategy are verified by simulations.

关 键 词：复杂电网 间谐波 并网逆变器 强迫振荡 有源阻尼 

分 类 号：TM464[电气工程—电器]