Abstract—Through this paper a novel technique for detecting and characterizing disturbances in power systems based on wavelet transforms is proposed. The voltage signal under investigation is often corrupted by noises, therefore the signal is first de-noised and then wavelet transform is applied. Using the first detail wavelet coefficients, voltage disturbance is detected and its duration is determined. The combination of an adaptive prediction filter based sub-band decomposition structure with a rule based histogram analysis block produce successful detection and classification results on our real life power system transient data. In this paper, voltage swell is considered for comparing both approaches. Proposed scheme is implemented using MATLAB, Simulink, DSP and Wavelet toolboxes.

Index Terms—Adaptive decomposition, Daubechies (Db),Discrete Wavelet Transform (DWT), Multi Resolution Analysis(MRA), Power Quality (PQ), Statistical methods.

Anoop Mathew is Head of the Electronics and Communication Engineering Department, VedaVyasa Institute of Technology, Karadparamba, Malappuram Dt; Kerala, India 673632 ( Phone :+91-9567398001, 0483 2832157; fax: 0483 2832156; e-mail:anoopmathew@ieee.org)
N. O. Gunasekar is Professor and Head of the Electrical and Electronics Engineering Department, Bharath University, Chennai-73D. Bensiker Raja Singh is working with Bharath University, Chennai-73as a lecturer in Electrical and Electronics Engineering Department.(Phone: +91-9486089841; e-mail: benzees003@gmail.com)
S. Uma Mageswaran is working with Bharath University, Chennai-73 as a lecturer in Electrical and Electronics Engineering Department. (Phone:+91-9840749738; e-mail: u.mag125@gmail.com)

Cite: Anoop Mathew, N.O. Gunasekar, D. Bensiker Raja Singh and S.Uma Mahaswaran, "Detection and Classification of Voltage Swells Using Wavelet Transforms," International  Journal  of  Computer  and  Electrical
Engineering vol. 2, no. 3, pp. 394-398, 2010.