Lightning Impulse Withstand of Natural Ester Liquid
Due to the low biodegradability of mineral oil, intense research is conducted to define alternative liquids with comparable dielectric properties. Natural ester liquids are an alternative in focus; they are used increasingly as insulating liquid in distribution and power transformers. The main advan...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-07-01
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| Series: | Energies |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1996-1073/11/8/1964 |
| _version_ | 1811187865222119424 |
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| author | Stephanie Haegele Farzaneh Vahidi Stefan Tenbohlen Kevin J. Rapp Alan Sbravati |
| author_facet | Stephanie Haegele Farzaneh Vahidi Stefan Tenbohlen Kevin J. Rapp Alan Sbravati |
| author_sort | Stephanie Haegele |
| collection | DOAJ |
| description | Due to the low biodegradability of mineral oil, intense research is conducted to define alternative liquids with comparable dielectric properties. Natural ester liquids are an alternative in focus; they are used increasingly as insulating liquid in distribution and power transformers. The main advantages of natural ester liquids compared to mineral oil are their good biodegradability and mainly high flash and fire points providing better fire safety. The dielectric strength of natural ester liquids is comparable to conventional mineral oil for homogeneous field arrangements. However, many studies showed a reduced dielectric strength for highly inhomogeneous field arrangements. This study investigates at which degree of inhomogeneity differences in breakdown voltage between the two insulating liquids occur. Investigations use lightning impulses with different electrode arrangements representing different field inhomogeneity factors and different gap distances. To ensure comparisons with existing transformer geometries, investigations are application-oriented using a transformer conductor model, which is compared to other studies. Results show significant differences in breakdown voltage from an inhomogeneity factor of 0.1 (highly inhomogeneous field) depending on the gap distance. Larger electrode gaps provide a larger inhomogeneity at which differences in breakdown voltages occur. |
| first_indexed | 2024-04-11T14:10:50Z |
| format | Article |
| id | doaj.art-ee7caf8b3fb146b1997333c30ea0af20 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-11T14:10:50Z |
| publishDate | 2018-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-ee7caf8b3fb146b1997333c30ea0af202022-12-22T04:19:44ZengMDPI AGEnergies1996-10732018-07-01118196410.3390/en11081964en11081964Lightning Impulse Withstand of Natural Ester LiquidStephanie Haegele0Farzaneh Vahidi1Stefan Tenbohlen2Kevin J. Rapp3Alan Sbravati4Institute of Power Transmission and High Voltage Technology, University of Stuttgart, 70569 Stuttgart, GermanyInstitute of Power Transmission and High Voltage Technology, University of Stuttgart, 70569 Stuttgart, GermanyInstitute of Power Transmission and High Voltage Technology, University of Stuttgart, 70569 Stuttgart, GermanyCargill Inc., Cargill Industrial Specialties—Dielectric Fluids, Plymouth, MN 55441, USACargill Inc., Cargill Industrial Specialties—Dielectric Fluids, Plymouth, MN 55441, USADue to the low biodegradability of mineral oil, intense research is conducted to define alternative liquids with comparable dielectric properties. Natural ester liquids are an alternative in focus; they are used increasingly as insulating liquid in distribution and power transformers. The main advantages of natural ester liquids compared to mineral oil are their good biodegradability and mainly high flash and fire points providing better fire safety. The dielectric strength of natural ester liquids is comparable to conventional mineral oil for homogeneous field arrangements. However, many studies showed a reduced dielectric strength for highly inhomogeneous field arrangements. This study investigates at which degree of inhomogeneity differences in breakdown voltage between the two insulating liquids occur. Investigations use lightning impulses with different electrode arrangements representing different field inhomogeneity factors and different gap distances. To ensure comparisons with existing transformer geometries, investigations are application-oriented using a transformer conductor model, which is compared to other studies. Results show significant differences in breakdown voltage from an inhomogeneity factor of 0.1 (highly inhomogeneous field) depending on the gap distance. Larger electrode gaps provide a larger inhomogeneity at which differences in breakdown voltages occur.http://www.mdpi.com/1996-1073/11/8/1964dielectric breakdown voltagedielectric liquidsnatural ester liquids vs. mineral oilpower transformersvegetable oils |
| spellingShingle | Stephanie Haegele Farzaneh Vahidi Stefan Tenbohlen Kevin J. Rapp Alan Sbravati Lightning Impulse Withstand of Natural Ester Liquid Energies dielectric breakdown voltage dielectric liquids natural ester liquids vs. mineral oil power transformers vegetable oils |
| title | Lightning Impulse Withstand of Natural Ester Liquid |
| title_full | Lightning Impulse Withstand of Natural Ester Liquid |
| title_fullStr | Lightning Impulse Withstand of Natural Ester Liquid |
| title_full_unstemmed | Lightning Impulse Withstand of Natural Ester Liquid |
| title_short | Lightning Impulse Withstand of Natural Ester Liquid |
| title_sort | lightning impulse withstand of natural ester liquid |
| topic | dielectric breakdown voltage dielectric liquids natural ester liquids vs. mineral oil power transformers vegetable oils |
| url | http://www.mdpi.com/1996-1073/11/8/1964 |
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