Detection and Improvement of Power Quality Disturbances using Wavelet Transform with Noise-Suppression Method

Recently power quality has become one of the most important issues in modern power industry. The origin of events which affect quality of power is mainly electromagnetic transients, harmonic distortion in addition to voltage sag, swell, flicker, and other power quality disturbances that proliferate in modern electric power grids. The WT is offering a large variety of potential bases, where optimization can be further performed.In the WT applications the process often confuses the transient signals and the noises ride on the signals.Consequently, the threshold is difficult to give in detecting the existence of transient signals. To eliminate the difficulty of distinguishing the signals from the noises existing in the Wavelet Transform Coefficients (WTCs) of the signals, a denoising algorithm is presented to suppress the noise riding on the signals. To further improve the disturbance detection rate by more effectively discriminating the signals from the noises after the DWT, a spatial-correlationbased noise-suppression algorithm is proposed in this paper.This work describes the techniques of correcting the supply voltage sag, swell in a distributed system. At present, a wide range of very flexible controllers, which capitalize on newly available power electronics components, are emerging for custom power applications. Among these, the distribution static compensator is the most effective devices. A D-STATCOM injects a current into the system to correct the voltage sag, swell. Comprehensive results are presented to assess the performance of device as a potential custom power solution.