In view of such issues as difficult accurate identification of transient power quality due to the factors of multiple types of disturbance and complicated noise environment of transient power quality disturbance of distribution network

a kind of accurate detection and identification method of transient power quality of intelligent distribution network based on multi-transformation and spectral kurtosis is studied deeply in this paper. The method firstly eliminate the noise in the signal through wavelet transform

then performs wavelet transform of the denoising signal to detect both amplitude and moment of transient power quality disturbance. By the use of the characteristic of the kurtosis such as sensitive to the impact component and strong to anti-noise ability

the transient pulse

transient oscillation and short time voltage fluctuations are identified by the kurtosis calculation

which is subject to the short time Fourier transformation of the denoising signal.The Hilbert-Huang transform of short-time voltage variation fluctuation is performed to detect the transient frequency and amplitude of voltage sag

voltage interruption and transient swell in the short voltage variation

thus identify the voltage sag

voltage interruption and voltage swell.The method avoids the useless detection of the HHT to transient pulse and transient oscillation and has such multiple advantages as simple process

high detection accuracy

high identification and strong commonality.