Investigation of Effects of Different High Voltage Types on Dielectric Strength of Insulating Liquids

Fatih Atalar (), Aysel Ersoy and Pawel Rozga
Additional contact information
Fatih Atalar: Department of Electrical and Electronic Engineering, Istanbul University-Cerrahpaşa, 34320 Istanbul, Turkey
Aysel Ersoy: Department of Electrical and Electronic Engineering, Istanbul University-Cerrahpaşa, 34320 Istanbul, Turkey
Pawel Rozga: Institute of Electrical Power Engineering, Lodz University of Technology, 90-537 Lodz, Poland

Energies, 2022, vol. 15, issue 21, 1-25

Abstract: Liquid dielectrics are different from each other, but are used to perform the same tasks in high-voltage electrical equipment, especially transformers. In similar conditions, the insulation performance of transformer oils under different types of voltage will provide dielectric resistance. In this study, three different dielectric liquids applied in transformers, namely mineral oil, natural ester and synthetic ester, were tested. Tests under AC and negative DC voltage were performed at electrode gaps of 2.5 mm, 2 mm and 1 mm using disk and VDE type electrodes as per ASTM D1816-84A and ASTM D877-87 standards, respectively. In turn, the impulse voltage tests were performed under an electrode configuration suggested by the IEC 60897 standard. The current data of 500 ms prior to breakdown under AC electrical field stress was decomposed using the empirical mode decomposition (EMD) and variational mode decomposition (VMD) methods. These analyses were conducted before the full electrical breakdown. Although synthetic ester has the highest dielectric strength under AC and negative DC electrical field stress, mineral oil has been assessed to be the most resistant liquid dielectric at lightning impulse voltages. In addition, stabilization of mineral oil under AC and negative DC voltage was also seen to be good with the help of calculated standard deviation values. However, synthetic ester has a significant advantage, especially in terms of dielectric performance, over mineral oil in spite of the stability of mineral oil. This indicates that liquid dielectric selection for transformers must be carried out as a combined evaluation of multiple parameters.

Keywords: dielectric liquid; transformer; breakdown voltage; partial discharge; electrical stress (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://www.mdpi.com/1996-1073/15/21/8116/pdf (application/pdf)
https://www.mdpi.com/1996-1073/15/21/8116/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:15:y:2022:i:21:p:8116-:d:959204

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().