Scientific Journal of KubSAU

This article presents an algorithm based on the discrete wavelet transform for the analysis of current root mean square (RMS) value and total harmonic distortion (THD) in power systems. Power quality indices play an important role in case of non-stationary distorted waveforms, where neither a frequency-domain-based approach using fast Fourier transform tools nor a timedomain-based approach using real time data give satisfactory results. The algorithm proposed decomposes the current waveforms into uniform frequency bands corresponding to the odd harmonic components of the signal. The proposed algorithm overcomes the spectra leakage problem. Computer simulations verified the effectiveness of the proposed algorithm

This article utilizes wavelet analysis, a relatively new mathematical tool, designed to develop an algorithm of analysis for electrical transients in electric power systems. Techniques, which are currently used, fall into two main categories: time domain or the integral transform domain. Both of the aforementioned categories can be stressed when solving equations with a wide spectrum or when a system of equations is subjected to a nonstationary forcing function. One of the benefits of wavelet analysis, however, is the ability to resolve nonstationary nature signals easily. Based on the discrete time domain approximation, the system components such as resistor and inductor are modeled in discrete wavelet domain for purpose of transient analysis. The method can be implemented by any kind of orthogonal wavelet transform. Computer simulations verified the effectiveness of the proposed method. The proposed algorithm can be implemented to calculate the shortcircuits in electric power systems