Wavelet technique for noise separation in the neutral current of a power transformer during impulse test

Author

Bhoomaiah, A. ; Sreelatha, G. ; Naidu, P. Appala ; Rao, M. Mohan ; Singh, B.P.

Author_Institution

Corp. Res. & Dev. Center, Bharat Heavy Electr. Ltd., Hyderabad, India

fYear

2005

fDate

16-19 Oct. 2005

Firstpage

577

Lastpage

580

Abstract

A power transformer is the most important component in an EHV power transmission. During impulse test the neutral current is compared at reduced and full impulse voltages. Any difference in the neutral current is construed as failure of transformer. In this paper, identification and separation of a noise signal from the main neutral current are carried out using wavelet technique. In order to carry out analysis, faults are created in turns of the tapping winding of a 61 MVA, 11/220 kV generator transformer (GT) at different locations. Neutral currents are recorded by applying low voltage impulse through recurrent surge generator (RSG). Contribution of each frequency in time domain signal is calculated by applying Gabor wavelet. The proposed method can be used for isolating the contribution due to any frequency in the waveform.

Keywords

impulse noise; impulse testing; neutral currents; power transformer testing; power transmission faults; pulse generators; wavelet transforms; Gabor wavelet; fault; generator transformer; impulse test; neutral current; noise separation; power transformer; power transmission; recurrent surge generator; tapping winding; time domain signal; wavelet technique; Equations; Fault detection; Frequency; Impulse testing; Power transformer insulation; Power transformers; Signal processing; Wavelet analysis; Wavelet domain; Wavelet transforms;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulation and Dielectric Phenomena, 2005. CEIDP '05. 2005 Annual Report Conference on

Print_ISBN

0-7803-9257-4

Type

conf

DOI

10.1109/CEIDP.2005.1560748

Filename

1560748