Journal ArticleDOI
Bivariate dependent rate analyses for fault identification in transformer windings during impulse test
TLDR
In this paper, the bivariate dependent rate analyses are proposed to identify the failure in transformer windings, which enable the calculation of winding response due to any impulse voltage excitation of full wave (FW) and chopped wave impulse (CW) for typical transformers.Abstract:
Identification of winding insulation failure during lightning impulse testing of transformer has been an important issue over a long period of time. It requires a significant human expertise and knowledge for proper judgment of transformer insulation. In this paper, the bivariate dependent rate analyses are proposed to identify the failure in transformer windings. The proposed analyses enable the calculation of winding response due to any impulse voltage excitation of full wave (FW) and chopped wave impulse (CW) for typical transformers. Initially, the line of best-fit on the scatter diagram is utilized to visualize the similarities between the measured winding responses and also to identify the type of relationship with potential outliers. Further, ellipse analysis is utilized to calculate the diversification (size, shape and orientation) between the responses. The actual interdependency between winding responses is established through nonlinear interpretation coefficients. To prove the feasibility of the analyses, 66.7 MVA, 90 MVA, 150 MVA, 250 MVA transformers, 80 MVAr reactor and 22 kV interleaved winding are used.read more
Citations
More filters
Journal ArticleDOI
Wavelet power ratio signature spectrum analysis for prediction of winding insulation defects in transformer and shunt reactor
TL;DR: In this paper, a wavelet power ratio signature spectrum analysis is proposed to identify the short duration of partial discharge (PD) pulses of 170 ns and 30 ns within windings due to impulse voltage excitation.
Journal ArticleDOI
Statistical correlation technique for transient signal analysis during impulse testing of transformers
TL;DR: In this article, a statistical correlation technique is proposed to estimate the best correlation between transient signals for passed (withstood the impulse voltage) or failed (not withstood) conditions of the insulations.
Proceedings ArticleDOI
Acoustic emission techniques for transformers during lightning impulse voltage excitation
TL;DR: In this paper, the location of the partial discharge (PD) source during impulse voltage excitation using acoustic emission (AE) technique is investigated. But, it is difficult to locate the position of the PD source accurately.
Proceedings ArticleDOI
Polynomial pattern recognition analyses for evaluation of transient signals in transformers
TL;DR: In this paper, a polynomial pattern recognition analysis is proposed for identification of transformer winding insulation failure during lightning impulse testing of transformer, which enables the computation of winding responses (transient signal) measured at neutral terminal of the transformer winding due to impulse voltage excitation.
References
More filters
Book
Large Power Transformers
K. Karsai,D. Kerényi,László Kiss +2 more
TL;DR: In this paper, the physical background of Transformer operation is discussed, including the core, the windings, and the insulation of the Transformer's structural parts, as well as the temperature rise and cooling of Transformers.
Journal ArticleDOI
Partial discharge localization in transformers using UHF detection method
TL;DR: In this article, three different methods of acquiring the time differences of arrival (TDOA) from the PD waveforms are discussed, including the first peak of the signal as the arrival instant, or from the cross-correlation of the PD signal waveforms, or by applying the similarity function to the plots of PD signals cumulative energy.
Journal ArticleDOI
Frequency domain correlation technique for PD location in transformer winding
V. Jeyabalan,S. Usa +1 more
TL;DR: In this article, the limitation of time domain correlation method in locating partial discharge (PD) in transformer windings is found out, and frequency domain correlation with Gram Schmidt orthogonalization is proposed.
Journal ArticleDOI
Lineage‐dependent rates of evolutionary diversification: analysis of bivariate ellipses
Robert E. Ricklefs,P. Nealen +1 more
TL;DR: Ellipse analysis can provide a more detailed characterization of trait evolution than other comparative methods, taking advantage of the additional information provided by the shape and, in some cases, the dimensions of the bivariate ellipse.