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Improved Monitoring and Diagnosis of Transformer Solid Insulation Using Pertinent Chemical Indicators

Authors :
Vahid Behjat
Reza Emadifar
Mehrdad Pourhossein
U. Mohan Rao
Issouf Fofana
Reza Najjar
Source :
Energies, Vol 14, Iss 13, p 3977 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

Transformers are generally considered to be the costliest assets in a power network. The lifetime of a transformer is mainly attributable to the condition of its solid insulation, which in turn is measured and described according to the degree of polymerization (DP) of the cellulose. Since the determination of the DP index is complex and time-consuming and requires the transformer to be taken out of service, utilities prefer indirect and non-invasive methods of determining the DP based on the byproduct of cellulose aging. This paper analyzes solid insulation degradation by measuring the furan concentration, recently introduced methanol, and dissolved gases like carbon oxides and hydrogen, in the insulating oil. A group of service-aged distribution transformers were selected for practical investigation based on oil samples and different kinds of tests. Based on the maintenance and planning strategy of the power utility and a weighted combination of measured chemical indicators, a neural network was also developed to categorize the state of the transformer in certain classes. The method proved to be able to improve the diagnostic capability of chemical indicators, thus providing power utilities with more reliable maintenance tools and avoiding catastrophic failure of transformers.

Details

Language :
English
ISSN :
19961073
Volume :
14
Issue :
13
Database :
Directory of Open Access Journals
Journal :
Energies
Publication Type :
Academic Journal
Accession number :
edsdoj.2c8b2927e8a4d85973aa445344e2066
Document Type :
article
Full Text :
https://doi.org/10.3390/en14133977