Since the access of renewable energy to the microgrid will bring many power quality problems

it is therefore necessary to detect and identify the power quality signal of the microgrid.However

it is highly susceptible to noise interference during the process of collecting and detecting the power quality signal.Reducing effectively the noise in the signal and completely retaining the singular point reflecting the sudden change of the signal is the basis for detecting the power quality disturbance.The traditional detection method is basically only applicable to steady-state power quality disturbance with low noise immunity.In order to improve the detection accuracy under noise conditions

in this paper a method based on wavelet transform and Hilbert-Huang transform to detect and identify transient power quality disturbance in microgrid is proposed.The method uses wavelet threshold de-noising method to eliminate signal noise and uses wavelet transform and Hilbert-Huang transform to identify and detect the transient power quality disturbance of microgrid.At the same time

computer simulation is carried out.It is shown by the simulation result that the method has remarkable de-noise effect

significant identific ation effect

high detection precision and strong practic ability.