Insulation characteristics of epoxy insulator with internal crack-shaped micro-defects - study on the equivalence of accelerated degradation by frequency acceleration test.
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| Title: | Insulation characteristics of epoxy insulator with internal crack-shaped micro-defects - study on the equivalence of accelerated degradation by frequency acceleration test. |
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| Authors: | Ueta, Genyo1, Wada, Junichi1, Okabe, Shigemitsu1, Miyashita, Makoto2, Nishida, Chieko2, Kamei, Mitsuhito2 |
| Source: | IEEE Transactions on Dielectrics & Electrical Insulation. Jun2014, Vol. 21 Issue 3, p1216-1225. 10p. |
| Subjects: | Epoxy insulators, Acceleration (Mechanics), Fracture mechanics, Partial discharges, Breakdown voltage |
| Abstract: | Generally, insulating spacers of gas insulated switchgear (GIS) have outstanding durability and are not considered prone to insulation failure within a design life of about 30 years, provided the products conform and have passed the partial discharge (PD) test. However, to assume operation over 30 years, degradation characteristics are important in cases where an extremely microscopic defect below the detection level in the PD test is present or produced inside the insulator. Accordingly, to date, the authors have obtained the breakdown voltagetime (V-t) characteristics using epoxy insulators provided with three types of micro-defect (crack, void, and delamination); the apparent PD of which is equivalent to 1 pC for an actual 550 kV-GIS spacer. It emerged based on these V-t characteristics that the breakdown risk peaked for a crack defect among those three types of shape and that it was essential to obtain data on long-term breakdown characteristics at the actual operating electric field level to rigorously evaluate the breakdown risk under long-term operation. Therefore, this paper includes a study on the equivalence of accelerated degradation by frequency acceleration as a means of determining the long-term breakdown characteristics. In the study, the dependency of various PD characteristics on frequency was initially examined by changing the frequency of the applied voltage within the range 60 to 3000 Hz. Consequently, the increase in the number of PDs per unit time proportional to frequency could be confirmed without any abnormal phenomena, such as suspended discharge, observed within the frequency range this time. In other words, it was clarified that the degradation due to PD could be accelerated by increasing the frequency. Subsequently, breakdown tests were conducted with frequency as a parameter to evaluate the frequency up to which the equivalence of accelerated degradation could be maintained based on breakdown times. As a result, it was found that the equivalence of acceleration degradation by frequency acceleration was valid in acceleration at up to 1500 Hz because the breakdown time was shortened in reverse proportion to the frequency. [ABSTRACT FROM AUTHOR] |
| Copyright of IEEE Transactions on Dielectrics & Electrical Insulation is the property of IEEE and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 96647282 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Insulation characteristics of epoxy insulator with internal crack-shaped micro-defects - study on the equivalence of accelerated degradation by frequency acceleration test. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Ueta%2C+Genyo%22">Ueta, Genyo</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Wada%2C+Junichi%22">Wada, Junichi</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Okabe%2C+Shigemitsu%22">Okabe, Shigemitsu</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Miyashita%2C+Makoto%22">Miyashita, Makoto</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Nishida%2C+Chieko%22">Nishida, Chieko</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Kamei%2C+Mitsuhito%22">Kamei, Mitsuhito</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22IEEE+Transactions+on+Dielectrics+%26+Electrical+Insulation%22">IEEE Transactions on Dielectrics & Electrical Insulation</searchLink>. Jun2014, Vol. 21 Issue 3, p1216-1225. 10p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Epoxy+insulators%22">Epoxy insulators</searchLink><br /><searchLink fieldCode="DE" term="%22Acceleration+%28Mechanics%29%22">Acceleration (Mechanics)</searchLink><br /><searchLink fieldCode="DE" term="%22Fracture+mechanics%22">Fracture mechanics</searchLink><br /><searchLink fieldCode="DE" term="%22Partial+discharges%22">Partial discharges</searchLink><br /><searchLink fieldCode="DE" term="%22Breakdown+voltage%22">Breakdown voltage</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Generally, insulating spacers of gas insulated switchgear (GIS) have outstanding durability and are not considered prone to insulation failure within a design life of about 30 years, provided the products conform and have passed the partial discharge (PD) test. However, to assume operation over 30 years, degradation characteristics are important in cases where an extremely microscopic defect below the detection level in the PD test is present or produced inside the insulator. Accordingly, to date, the authors have obtained the breakdown voltagetime (V-t) characteristics using epoxy insulators provided with three types of micro-defect (crack, void, and delamination); the apparent PD of which is equivalent to 1 pC for an actual 550 kV-GIS spacer. It emerged based on these V-t characteristics that the breakdown risk peaked for a crack defect among those three types of shape and that it was essential to obtain data on long-term breakdown characteristics at the actual operating electric field level to rigorously evaluate the breakdown risk under long-term operation. Therefore, this paper includes a study on the equivalence of accelerated degradation by frequency acceleration as a means of determining the long-term breakdown characteristics. In the study, the dependency of various PD characteristics on frequency was initially examined by changing the frequency of the applied voltage within the range 60 to 3000 Hz. Consequently, the increase in the number of PDs per unit time proportional to frequency could be confirmed without any abnormal phenomena, such as suspended discharge, observed within the frequency range this time. In other words, it was clarified that the degradation due to PD could be accelerated by increasing the frequency. Subsequently, breakdown tests were conducted with frequency as a parameter to evaluate the frequency up to which the equivalence of accelerated degradation could be maintained based on breakdown times. As a result, it was found that the equivalence of acceleration degradation by frequency acceleration was valid in acceleration at up to 1500 Hz because the breakdown time was shortened in reverse proportion to the frequency. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of IEEE Transactions on Dielectrics & Electrical Insulation is the property of IEEE and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1109/TDEI.2014.6832268 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 1216 Subjects: – SubjectFull: Epoxy insulators Type: general – SubjectFull: Acceleration (Mechanics) Type: general – SubjectFull: Fracture mechanics Type: general – SubjectFull: Partial discharges Type: general – SubjectFull: Breakdown voltage Type: general Titles: – TitleFull: Insulation characteristics of epoxy insulator with internal crack-shaped micro-defects - study on the equivalence of accelerated degradation by frequency acceleration test. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Ueta, Genyo – PersonEntity: Name: NameFull: Wada, Junichi – PersonEntity: Name: NameFull: Okabe, Shigemitsu – PersonEntity: Name: NameFull: Miyashita, Makoto – PersonEntity: Name: NameFull: Nishida, Chieko – PersonEntity: Name: NameFull: Kamei, Mitsuhito IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2014 Type: published Y: 2014 Identifiers: – Type: issn-print Value: 10709878 Numbering: – Type: volume Value: 21 – Type: issue Value: 3 Titles: – TitleFull: IEEE Transactions on Dielectrics & Electrical Insulation Type: main |
| ResultId | 1 |
