Analysis of Forced Power Oscillation Based on FFT

Abstract

Low-frequency oscillations occur frequently in many interconnected power grids around the world. In severe cases, even system-wide chain reactions are triggered, resulting in system unwinding and large-scale blackouts. In this paper, a FFT-based forced power oscillation disturbance source localization method is introduced. Using the active power and frequency of the steady-state oscillation phase of the low-frequency oscillation, the dominant component of the oscillation is obtained by the fast Fourier transform (FFT), and then the disturbance source is automatically positioned according to the energy function. Taking the low-frequency oscillation accident occurring in Hunan power grid as an example, the energy function based on FFT and the traditional energy function method are compared, which shows that the proposed method can locate the disturbance source more accurately.