Volume 07, December 2010

Permanent URI for this collectionhttp://dspace.iiuc.ac.bd/handle/88203/69

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Author: search.filters.author.Uddin, Muhammad Athar

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    Power System Switching Transient Detection using Wavelet Transformed Based Signal Decomposition
    (CRP, International Islamic University Chittagong, Bangladesh, 2010-12) Alam, M Shafiul; Chowdhury, Md Shamimul Haque; Uddin, Muhammad Athar
    Switching transient phenomena in Electric Power System develop several disturbances, sometimes very hazardous for the electrical equipment life, for the environment and for the human life. Switching transient phenomena produce over voltage, over current and electrical fields, which haven't to neglect. Several types of wavelet network algorithms have been considered for detection of power system switching transients. But both time and frequency information are accessible by multiresolution analysis (MRA). This paper presents a wavelet transform based multiresolution analysis of power system signal to detect, localize and extract switching transients. Power system switching transients have been simulated using MATLAB-7.01. The key idea underlying the approach is to decompose a distorted signal into other signals which represents a smoothed version and detailed version of the original signal. The decomposition is performed using multiresolution analysis. The proposed method appears to be robust for detection and localization of power quality disturbances produced due to load switching and capacitor switching.
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    Design, Implementation and Performance Analysis of a Low-cost Optical Tachometer
    (CRP, International Islamic University Chittagong, Bangladesh, 2010-12) Bakibillah, A. S. M.; Uddin, Muhammad Athar; Haque, Shah Ahsanul
    Electrical and mechanical machineries are used in industrial and domestic applications. Measurement of speed of revolving machineries is necessary for their proper functioning and controlling. Tachometer is an instrument which is used to measure the speed of revolving shaft, gear and pulley. This paper describes the basic construction of a low cost optical tachometer and analyzes its performance. The basic tachometer circuit consists of two stages. In the first stage monostable wired around IC NE555 is used, and in the second stage a digital counter based 4-digit counter IC 74C926 is used for the construction of the tachometer. A 5V regulated power supply circuit and an infrared light source circuit are also used. The instrument can measure speed upto 9999 RPM. This speed measurement instrument performs well in terms of accuracy, and can be very useful due to its simplicity and low cost.