Understanding moisture dynamics and its effect on dielectric response of transformer insulation

Cui, Yi, Ma, Hui, Saha, Tapan and Ekanayake, Chandima (2015) Understanding moisture dynamics and its effect on dielectric response of transformer insulation. IEEE Transactions on Power Delivery, 30 5: 2195-2204. doi:10.1109/TPWRD.2015.2426199


Author Cui, Yi
Ma, Hui
Saha, Tapan
Ekanayake, Chandima
Title Understanding moisture dynamics and its effect on dielectric response of transformer insulation
Journal name IEEE Transactions on Power Delivery   Check publisher's open access policy
ISSN 0885-8977
1937-4208
Publication date 2015-04-24
Year available 2015
Sub-type Article (original research)
DOI 10.1109/TPWRD.2015.2426199
Open Access Status Not Open Access
Volume 30
Issue 5
Start page 2195
End page 2204
Total pages 10
Place of publication Piscataway NJ United States
Publisher Institute of Electrical and Electronics Engineers
Collection year 2016
Language eng
Abstract Dielectric response measurement has recently been adopted by utilities for evaluating moisture content in cellulose insulation (paper and pressboard) of transformers. Moisture distribution is highly dependent on temperature. Since the temperature inside a transformer may change during the dielectric response measurement, the moisture in the transformer’s cellulose and oil insulation can hardly attain an equilibrium state. Instead, moisture dynamics exist inside the transformer: (1) cellulose absorbs (desorbs) moisture from (to) oil with the changes in temperature; and (2) moisture migrates inside cellulose due to a moisture gradient. This paper investigates moisture dynamics and its effect on dielectric response of a transformer’s cellulose insulation. It proposes a distributed parameter model to reveal the correlation between moisture distribution (under non-equilibrium conditions due to thermal transients) and dielectric response parameters (dielectric losses and permittivity) of cellulose insulation. It then estimates these parameters under moisture non-equilibrium conditions. The accelerated ageing and moisture diffusion experiments are conducted on a prototype transformer to verify the proposed model. The methodology developed in this paper can help the proper interpretation of dielectric response measurement of field transformers under thermal transients.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Information Technology and Electrical Engineering Publications
 
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Created: Wed, 20 May 2015, 20:36:55 EST by Yi Cui on behalf of School of Information Technol and Elec Engineering