孤岛检测是分布式光伏并网发电中的重要问题.为此,研究复小波变换和实小波变换在孤岛检测中的应用,提取并分析公共耦合点电压小波变换系数的幅值和相位的对比关系,以判断孤岛是否发生.仿真结果表明:基于复小波变换的孤岛检测可解决实小波方法特征信号分层繁琐和阈值选取过程复杂的问题.
Islanding detection is an important issue in grid-connection of a distributed photovoltaic system. The paper compares complex and real wavelet transforms used in islanding detection. Islanding is judged by extracting and analyzing changes in the amplitude and phase of wavelet transform coefficients of the voltage at common coupling points. Simulation results show that the islanding detection method based on complex wavelet transform is more effective than that based on real wavelet transform. The complex wavelet method also solves the problem of tedious layering of characteristic signal and complicated threshold selection encountered in the real wavelet based method.
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