Locating transformer faults through sensitivity analysis of high frequency modeling using transfer function approach

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:524567

Islam, S M; Ledwich, G ^[1]

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1. Univ. of Newcastle, Callaghan, New South Wales (Australia)

Online condition monitoring of power transformers can give early warning of electrical failure and could prevent catastrophic losses. Transfer function analysis offers the additional advantage of fault identification and location. High frequency resonance in a transformer can be modeled by analogue distributed winding concepts. Every transformer has an unique transfer function independent of the shape of the input waveform and can be evaluated through sweep and impulse tests. Results show that this transfer function changes by winding deformation, displacement, ground leakage, local breakdown and partial discharges, etc. Digital simulation of impulse and variable frequency transient response together with their fast fourier transform spectral analysis are used in this paper to identify transformer faults and characterize their influence on transfer function. Sliding fault through the winding revealed changes in the transfer function to help locate the fault location. This paper contributes to the development of high frequency transformer model capable of studying faults including partial discharges, deriving condition assessment of a previously untested transformer from the varied characteristic plots to assess remaining life of a power transformer.

• OSTI ID: 524567
• Report Number(s): CONF-960614--; ISBN 0-7803-3531-7
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
ELECTRIC DISCHARGES
ELECTRICAL FAULTS
MATHEMATICAL MODELS
ON-LINE MEASUREMENT SYSTEMS
SENSITIVITY ANALYSIS
TRANSFORMERS