基于多正弦信号注入的大功率并网逆变器电网阻抗在线测量技术研究  

On-line Measurement of Grid Impedance for Large Capacity Grid-tied Inverter Based on Multiple-sinusoidal Signal Injection

作　　者：张禹风 杨淑英[1] 谢震[1] 汪令祥[2] 张兴[1] ZHANG Yufeng;YANG Shuying;XIE Zhen;WANG Lingxiang;ZHANG Xing(National and Local Joint Engineering Laboratory for Renewable Energy Access to Grid Technology(Hefei University of Technology),Hefei 230041,Anhui Province,China;Sungrow Power Supply Co.,Ltd.,Hefei 230088,Anhui Province,China)

机构地区：[1]可再生能源接入电网技术国家地方联合工程实验室(合肥工业大学),安徽省合肥市230041 [2]阳光电源股份有限公司,安徽省合肥市230088

出　　处：《中国电机工程学报》2024年第10期4026-4037,I0023,共13页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2022YFB4202301)。

摘　　要：文中研究基于多正弦扰动信号注入的大功率并网逆变器电网阻抗测量技术。选取多正弦信号作为电压扰动,参考空间光场理论中的Gerchberg-Saxton相位恢复算法对扰动信号进行优化设计;剪辑函数作为其中的关键要素,能够决定扰动信号时域波峰的剪辑速度和剪辑能力;为提升上述性能,提出采用反正切函数代替传统算法中的对数剪辑函数,仿真结果表明,相位恢复算法的剪辑性能得到大幅提升;随后,通过逆变器将扰动信号注入电网,采用Gauss-Newton非线性最小二乘法对采集到的扰动信号特征谐波频率点的信息进行曲线拟合,获取当前电网阻抗信息;最后,于搭建的1.5 MW并网逆变器RT-Lab平台进行多弱电网场景下的阻抗测量实验,实验结果验证了此方案的有效性和准确性。This paper focuses on the impedance measurement technology of large capacity grid-tied inverter based on multiple-sinusoidal disturbance signal injection.In this paper,multiple-sinusoidal signal is selected as the voltage disturbance,designed by referring to the Gerchberg-Saxton phase recovery algorithm in the spatial light field theory.Clip function,as one of the key elements,can determine the clipping speed as well as the clipping capability of the time domain wave crest of the disturbance signal.In order to improve the above performance,an inverse tangent function is proposed to replace the logarithmic clip function in the conventional algorithm,with the simulation results suggesting that the clip performance of the phase recovery algorithm is substantially improved.Then,the Gauss-Newton nonlinear least square method is used to carry out curve fitting on the information of characteristic harmonic frequency points of the collected disturbance signal to obtain the current grid impedance following by disturbance signal injected into the grid through the inverter.In the end,the experiments of impedance measurement under multiple weak grid scenarios are conducted on the established RT-Lab platform of a 1.5 MW grid-tied inverter,and the experimental results verify the effectiveness and accuracy of this scheme.

关 键 词：大功率并网逆变器 电网阻抗测量 多正弦信号 扰动信号设计 曲线拟合 

分 类 号：TM46[电气工程—电器]