TY - JOUR

T1 - Thermally accelerated aging of insulation paper for transformers with different insulating liquids

AU - Münster, Tobias

AU - Werle, Peter

AU - Hämel, Kai

AU - Preusel, Jörg

N1 - Funding Information: Acknowledgments: The authors would like to express their gratitude to AiF/ZIM for the financial support as well as Weidmann Electrical Technology AG for the support with insulation materials and Analysen Service GmbH for the paper analyses. Funding Information: Research funded by Zentrale Innovationsprogramm Mittelstand (ZIM) des Bundesministeriums für Wirtschaft und Energie (BMWi) (ZF4039201LT5). Funding Information: Funding: Research funded by Zentrale Innovationsprogramm Mittelstand (ZIM) des Bundesminis-teriums für Wirtschaft und Energie (BMWi) (ZF4039201LT5).

PY - 2021/6/1

Y1 - 2021/6/1

N2 - The article presents issues related to the aging behavior of oil-paper insulations in transformers using different oil-and ester-based insulating fluids. Despite numerous conducted studies on the subject of oil-paper aging, the use of new insulating fluids is creating open questions. In addition, new liquids such as synthetic and natural esters, as well as oil of the newest generation, are being used. Furthermore, there is still little research on the formation of aging markers with this form of the dielectric. For this reason, in this contribution, oil-paper insulations with mineral oil-based insulating fluids, natural and synthetic esters, as well as oil from natural gas, are aged thermally accelerated at 130◦C over a duration of 15 weeks, by considering two cases of free-breathing and hermetically sealed transformers. Therefore, various aging markers are investigated to allow a condition assessment. The results show that differences exist between the fluids and design of the transformer, as in the aging rate of the paper and the formation of aging markers in the insulating liquid such as acids. These findings can be used to improve asset management strategies by a more precise determination of the aging state depending on the transformer type as well as the type of insulating fluid.

AB - The article presents issues related to the aging behavior of oil-paper insulations in transformers using different oil-and ester-based insulating fluids. Despite numerous conducted studies on the subject of oil-paper aging, the use of new insulating fluids is creating open questions. In addition, new liquids such as synthetic and natural esters, as well as oil of the newest generation, are being used. Furthermore, there is still little research on the formation of aging markers with this form of the dielectric. For this reason, in this contribution, oil-paper insulations with mineral oil-based insulating fluids, natural and synthetic esters, as well as oil from natural gas, are aged thermally accelerated at 130◦C over a duration of 15 weeks, by considering two cases of free-breathing and hermetically sealed transformers. Therefore, various aging markers are investigated to allow a condition assessment. The results show that differences exist between the fluids and design of the transformer, as in the aging rate of the paper and the formation of aging markers in the insulating liquid such as acids. These findings can be used to improve asset management strategies by a more precise determination of the aging state depending on the transformer type as well as the type of insulating fluid.

KW - Aging

KW - Degree of polymerization

KW - Mineral oil

KW - Natural ester

KW - Oil-paper

KW - Synthetic ester

KW - Thermal stress

KW - Transformer

UR - http://www.scopus.com/inward/record.url?scp=85107413708&partnerID=8YFLogxK

U2 - 10.3390/en14113036

DO - 10.3390/en14113036

M3 - Article

AN - SCOPUS:85107413708

VL - 14

JO - ENERGIES

JF - ENERGIES

SN - 1996-1073

IS - 11

M1 - 3036

ER -