Dielectric spectroscopic measurements on transformer oil-paper insulation under controlled laboratory conditions

authored by

A. Setayeshmehr, I. Fofana, C. Eichler, A. Akbari, H. Borsi, E. Gockenbach

Abstract

For reliable operation of power transformers, the condition of the insulation system is essential. This paper reports on a detailed study of the effect of ageing, temperature and moisture on frequency and time domain spectroscopic measurements carried out on oil-impregnated pressboard samples as well as on a distribution transformer under controlled laboratory conditions. Because field measurements are generally performed after de-energizing the transformer, extreme care is required in interpreting the results due to inherent temperature instabilities. To avoid large thermal variations that may affect the results, a customized adiabatic room was built around the transformer for measurements above the ambient. Capacitance ratio and direct current conductivity deduced from the spectroscopic measurements, helped to interpret the data. Because, low frequency measurements techniques are time consuming, alternative to a transfer of time domain data into frequency domain data was investigated.

Organisation(s)

High Voltage Engineering and Asset Management Section (Schering Institute)

External Organisation(s)

Universite du Quebec a Chicoutimi (UQAC)

Type

Article

Journal

IEEE Transactions on Dielectrics and Electrical Insulation

Volume

15

Pages

1100-1111

No. of pages

12

ISSN

1070-9878

Publication date

08.2008

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electrical and Electronic Engineering

Electronic version(s)

https://doi.org/10.1109/TDEI.2008.4591233 (Access: Unknown)