为了在短数据且存在白噪声的情况下检测大幅度谐波附近的小幅度间谐波,提出了采用插值FFT和多信号分类法(MUSIC)相结合的间谐波参数检测方法.首先,利用加Hanning窗的插值FFT检测出信号中的主要频率成分;然后,从原信号中减去这部分信号,利用MUSIC方法对剩余信号进行频率检测,得到的两部分频率即认为是原信号中包含的频率成分；最后,采用最小二乘法在频率已知的情况下检测各频率分量对应的幅度和相位.仿真结果表明:该方法能够在短数据噪声环境下检测出整数次谐波附近的间谐波,幅度和频率参数的估计结果能够满足测试精度的要求.%To detect interharmonics with low amplitude near to harmonics with high amplitude under white noise condition with short-duration data, a method based on interpolation FFT algorithm and multiple signal classification (MUSIC) algorithm was presented. Firstly, the primary frequency com ponents of signal were extracted from sampled signal by interpolation FFT algorithm with Hanning window. Then, the residual signal was derived by subtracting the main frequency components of sig nal from sampled signal, and the frequency components of residual signal were detected by MUSIC al gorithm. The primary frequency in th$ first step and the residual frequency in the second step were considered as the whole frequency components of sampled signal. Finally, the corresponding ampli tude and angle of each frequency was detected by least square method. Simulation result shows that the proposed method can detect the interharmonics near the integer harmonics under noise with short data and the estimated result for parameters of frequency and amplitude can meet the need of measur ing accuracy.
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