Hilbert-Huang Transform Based Application in Power System Fault Detection

The temporarily fault signals existing in high voltage lines and electric equipments are usually non-linear and non-stationary. Low frequency oscillation characteristic extraction from fault signals plays an important role in online fault monitoring and detection system designing. In this paper we propose a procedure to analyze power system fault signal by employing HTT method. The fault signal is firstly decomposed into intrinsic mode function (IMF) by the empirical mode decomposition (EMD) method. Then instantaneous frequency and instantaneous amplitude is obtained by Hilbert transform to compose Hilbert spectrum. Thus the transient caused by fault can be analyzed and further detected accurately through the instantaneous frequency and the time-frequency-amplitude spectra analysis. Experiments show promising results.