改进的负序电流扰动孤岛检测方法

发布时间：2019-04-08 19:33

【摘要】：工程中采用三相光伏并网系统负序电流扰动法进行孤岛检测,会由于负载变化和浪涌电流等因素造成公共连接(PCC)电压出现负序高频分量而导致孤岛误判。在研究负序电流扰动下负序分量提取和孤岛判断原理基础上,利用离散小波变换对时域信号高频分量变化有良好解析能力的特点,实时检测分析PCC电压高频分量并判断孤岛效应。基于Matlab/Simulink建立并网系统模型,在逆变器输出功率与负载输入功率相匹配的情况下进行孤岛模拟试验,应用Daubechies小波对PCC电压信号进行量化分析,选择出有效的小波高频信号域值作为孤岛检测量进行孤岛检测。试验结果表明该方法能快速、有效地检测到孤岛,并能有效防止对伪孤岛现象的误判。
[Abstract]:In the project, the negative sequence current disturbance method of three-phase photovoltaic grid-connected system is used to detect the islanding, which will lead to the island misjudgment due to the negative sequence high frequency component of the common connected (PCC) voltage due to the change of load and surge current and other factors. On the basis of studying the principle of extracting negative sequence component and judging island under the disturbance of negative sequence current, the discrete wavelet transform is used to analyze the variation of high frequency component in time domain signal. The high frequency component of PCC voltage is detected and analyzed in real time and the islanding effect is judged. A grid-connected system model based on Matlab/Simulink is established. The islanding simulation experiment is carried out when the output power of the inverter is matched with the input power of the load. The PCC voltage signal is quantitatively analyzed by using Daubechies wavelet. The effective wavelet high frequency signal domain value is selected as the islanding measurement for islanding detection. The experimental results show that this method can detect islands quickly and effectively, and can effectively prevent false island phenomenon from being misjudged.
【作者单位】：湖北工业大学太阳能高效利用湖北省协同创新中心;
【基金】：湖北省教育厅科技项目(D20121403) 湖北省科技厅项目(2010CDB05802)~~
【分类号】：TM732

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