Showing papers by "Sivaji Chakravorti published in 2003"
TL;DR: In this paper, the application of the concept of fractal geometry to analyze the properties of fault currents was described, where fractal features such as fractal dimension, lacunarity used for image surface recognition and the sliding window algorithm used for fractal analysis of waveform were employed for classification of transformer impulse faults.
Abstract: Transformers are usually subjected to lightning impulse tests after assembly for assessment of their insulation strength. In the case of a fault the resulting winding current gets changed to a certain extent. The pattern of the fault currents depends on the type of fault and its location along the length of the winding. This paper describes the application of the concept of fractal geometry to analyze the properties of fault currents. Fractal features such as fractal dimension, lacunarity used for image surface recognition and the sliding window algorithm used for fractal analysis of waveform have been employed for classification of transformer impulse faults. Experimental results obtained for a 3 MVA transformer and simulation results obtained for 3 MVA, 5 MVA and 7 MVA transformers are presented to illustrate the ability of this approach to classify insulation failures. The results indicate that this new approach possesses reasonable abilities for waveform pattern discrimination.
34 citations
TL;DR: In this article, a wavelet transform is used to classify the patterns inherent in different fault currents during impulse testing of distribution transformers, and results for simulated models of a range of distribution transformer models are presented to illustrate the ability of this approach to classify insulation failures under impulse stresses.
Abstract: This letter presents a novel approach using the wavelet transform to classify the patterns inherent in different fault currents during impulse testing of distribution transformers. Results for simulated models of a range of distribution transformers are presented to illustrate the ability of this approach to classify insulation failures under impulse stresses.
14 citations
TL;DR: In this article, an expert system (ES) approach is adopted to develop a computer based intelligent technique for interpretation of minor impulse faults in distribution transformers, which can significantly enhance the safety, reliability, and economics of power systems.
9 citations