An Approach for Identification of Broadband Oscillation in Power System Based on Hanning Window Double-spectrum-line Interpolation FFT

The fast Fourier transform (FFT) is the main method of electrical signal analysis, but there are difficulties in performing non-synchronized sampling when FFT is applied to analyze broadband oscillation. In this paper, the broadband oscillation model of power system was established, and non-synchronous sampling problem was introduced. The sidelobe characteristic of Hanning window and the double-spectrum-line interpolation algorithm were both discussed, an approach for identification of broadband oscillation in power system based on Hanning window double-spectrum-line interpolation FFT was proposed, the applicable rectification formulas of the Hanning window double-spectrum-line interpolation was obtained by using polynomial curve fit function. The verification study showed that the algorithm proposed in this research was highly accurate when signals were sampled non-synchronously.