Voltage disturbance identification using fast fourier transform (FFT) and wavelet transform

Power quality is among the main things that is emphasized and is taken into consideration by utilities in order to meet the demands of their customer. At each passing day this issue has becoming more serious and at the same time the user’s demand on power quality also gets more critical. Thus it is...

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Bibliographic Details
Main Author: Abdullah, Farrah Salwani
Format: Thesis
Published: 2011
Subjects:
Online Access:http://eprints.uthm.edu.my/1729/
http://eprints.uthm.edu.my/1729/1/farrah_salwani.pdf
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Summary:Power quality is among the main things that is emphasized and is taken into consideration by utilities in order to meet the demands of their customer. At each passing day this issue has becoming more serious and at the same time the user’s demand on power quality also gets more critical. Thus it is essential to establish a power quality monitoring system to detect power quality disturbance. Several research studies regarding the power quality have been done before and their aims frequently concentrated on the collection of raw data for a further analysis, so the impacts of various disturbances can be investigated. This study presents the identification of voltage disturbance based on mathematical method of Wavelet Transform and Fast Fourier Transform (FFT). A simple program is developed based on these two methods using MATLAB 7.8 software. The recorded data used is taken from 22kv and 33kv TNB Distribution System in Skudai and focused on three major voltage disturbances which are voltage sag, voltage swell and voltage harmonic. Wavelet Transform and FFT will extract and localized the features of voltage disturbance occur in the recorded data. The recorded data contains voltage sag, voltage swell and harmonic is analyzed using FFT to extract its magnitude and frequency components of the disturbance. To locate the start time, end time, duration and magnitude of the voltage disturbance occur on the recorded data, the Wavelet Transform algorithm is applied. At the end of the study, a comparative analysis of the recorded data between Wavelet Transform and FFT methods used is reported to highlight the strength and weakness of each method. Besides that, the comparative analysis is done within these two methods to select the best and effective method to localize and extract the voltage disturbance.