频率波动下基于并网逆变器的电网阻抗在线测量方法  

On-line measurement method of grid impedance based on grid-connected inverter under frequency fluctuation

作　　者：孟良 胡雪凯 肖霖涛 肖国春[2] 高子鹏 姬朋坤 MENG Liang;HU Xuekai;XIAO Lintao;XIAO Guochun;GAO Zipeng;JI Pengkun(State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021,China;School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]国网河北省电力有限公司电力科学研究院,河北石家庄050021 [2]西安交通大学电气工程学院,陕西西安710049

出　　处：《电力自动化设备》2024年第11期149-156,共8页Electric Power Automation Equipment

基　　金：国家电网有限公司科技项目(TSS2022⁃09)。

摘　　要：电网频率波动和测量频率对电网工频阻抗的准确测量有着较大的影响。为此,对影响电网阻抗测量准确度的主要原因进行了理论分析,提出了一种基于互补电流信号注入的在线阻抗测量方法。该方法通过在基波电流相位相同处注入相邻的两段互补扰动电流,运用基波消去的方法降低了基波泄漏影响,相对地提高了测量信噪比;在减小电网频率波动对测量影响的同时,使测量频率可以更加接近工频。通过对比仿真和实验,证明该方法在实际电网工频阻抗测量中具有更高的准确度。The grid frequency fluctuation and measurement frequency have a great influence on the accurate measurement of power frequency impedance.Therefore,the main reasons affecting the accuracy of grid impedance measurement are analyzed theoretically,and an online impedance measurement method based on complementary current signal injection is proposed.This method injects two adjacent complementary distur⁃bance currents at the same phase of the fundamental current,and uses the method of fundamental elimination to reduce the influence of fundamental leakage,which relatively improves the measurement signal-to-noise ratio.While reducing the influence of grid frequency fluctuation on measurement,the measurement frequency can be closer to the power frequency.Through comparative simulation and experiment,it is proved that the proposed method has higher accuracy in the measurement of power frequency impedance of actual power grid.

关 键 词：工频阻抗 频率波动 测量频率 互补电流信号注入 在线阻抗测量 

分 类 号：TM464[电气工程—电器] TM934.7