Dielectric strength of transformer insulation at DC polarity reversal

Hasegawa, T.; Hatano, Masayuki; Yamaji, K.; Kouan, Toyokazu; Hosokawa, N.

doi:10.1109/61.634171

Cited by 35 publications

(14 citation statements)

References 3 publications

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“…As increasing temperature, K PDC is increased because quantities of space charge formation may be reduced by thermal activated detrapping of electrons. 16,17) From Fig. 4 and Table III, it is considered that nano-sized Al 2 O 3 particles may be act as shallow trap rather than deep trap.…”

Section: Breakdown and Polarity Reversal Breakdownmentioning

confidence: 99%

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

Park¹,

Kwon²,

Sim³

et al. 2014

Jpn. J. Appl. Phys.

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We have discussed a cross-linked polyethylene (XLPE) nanocomposite insulating material that is able to DC voltage applications. Nanocomposites, which are composed in polymer matrix mixed with nano-fillers, have received considerable attention because of their potential benefits as dielectrics. The nano-sized alumina oxide (Al 2 O 3 )/XLPE nanocomposite was prepared, and three kinds of test, such as DC breakdown, DC polarity reversal breakdown, and volume resistivity were performed. By the addition of nano-sized Al 2 O 3 filler, both the DC breakdown strength and the volume resistivity of XLPE were increased. A little homogeneous space charge was observed in Al 2 O 3 /XLPE nanocomposite material in the vicinity of electrode through the polarity reversal breakdown test. From these results, it is thought that the addition of Al 2 O 3 nano-filler is effective for the improvement of DC electrical insulating properties of XLPE.

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Section: Breakdown and Polarity Reversal Breakdownmentioning

confidence: 99%

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

Park¹,

Kwon²,

Sim³

et al. 2014

Jpn. J. Appl. Phys.

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“…Due to the limitations in testing equipment, the earlier investigations focus on the breakdown characteristics of OIP under single or simple voltage waveforms (DC, AC, and steep front impulse etc.) [4][5][6][7][8]. Among these investigations, Kurita et al investigated DC breakdown characteristics of OIP and discovered that DC breakdown voltage along paper layers is not as high as that through the laminated paper layers [6].…”

Section: Introductionmentioning

confidence: 99%

“…[4][5][6][7][8]. Among these investigations, Kurita et al investigated DC breakdown characteristics of OIP and discovered that DC breakdown voltage along paper layers is not as high as that through the laminated paper layers [6]. Moreover, it was found that the DC breakdown voltage along a paper layer is approximately equal to that of transformer oil.…”

Section: Introductionmentioning

confidence: 99%

Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

Zhu

Min

et al. 2018

Energies

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Based on the existing acknowledgment that space charge modulates AC and DC breakdown of insulating materials, this investigation promotes the related investigation into the situations of more complex electrical stress, i.e., AC-DC combined voltages. Experimentally, the AC-DC breakdown characteristics of oil impregnated paper insulation were systematically investigated. The effects of pre-applied voltage waveform, AC component ratio, and sample thickness on AC-DC breakdown characteristics were analyzed. After that, based on an improved bipolar charge transport model, the space charge profiles and the space charge induced electric field distortion during AC-DC breakdown were numerically simulated to explain the differences in breakdown characteristics between the pre-applied AC and pre-applied DC methods under AC-DC combined voltages. It is concluded that large amounts of homo-charges are accumulated during AC-DC breakdown, which results in significantly distorted inner electric field, leading to variations of breakdown characteristics of oil impregnated paper insulation. Therefore, space charges under AC-DC combined voltages must be considered in the design of converter transformers. In addition, this investigation could provide supporting breakdown data for insulation design of converter transformers and could promote better understanding on the breakdown mechanism of insulating materials subjected to AC-DC combined voltages.

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“…However, the values of En along surface of spacer A and B obviously exceed 1 MV/m in many points, which can lead to serious charge accumulation along the spacer surface after long-term dc voltage application [11].…”

Section: Electric Field Distribution Of Alumina Filled Epoxy Resin Spmentioning

confidence: 99%

Shape Optimization of the Spacer of 220 kV DC GIL

Jia¹

2017

dtetr

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ABSTRACT* Both experimental and numerical studies demonstrate that electric field formation mechanisms and insulation behavior at SF6/epoxy interface are substantially different for ac and dc voltage excitations. In this paper, based on fixed dc GIL dimensions and spacer-electrode joints, three types of alumina filled epoxy resin spacers with different shapes were designed with FEA software in order to find a way to provide a reliable spacer performance in HVDC gas insulated systems. The generalized design criteria for dc spacers were put forward. Results show that shape design of spacer in dc GIL is distinct from that in ac GIL. Moreover, distinctions between dc spacer and ac one in shape design are proposed, which could be beneficial for practical use of dc GIL.

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Dielectric strength of transformer insulation at DC polarity reversal

Cited by 35 publications

References 3 publications

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

Shape Optimization of the Spacer of 220 kV DC GIL

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Dielectric strength of transformer insulation at DC polarity reversal

Cited by 35 publications

References 3 publications

DC conduction and breakdown characteristics of Al2O3/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

DC conduction and breakdown characteristics of Al2O3/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

Space Charge Modulated Electrical Breakdown of Oil Impregnated Paper Insulation Subjected to AC-DC Combined Voltages

Shape Optimization of the Spacer of 220 kV DC GIL

Contact Info

Product

Resources

About

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation

DC conduction and breakdown characteristics of Al₂O₃/cross-linked polyethylene nanocomposites for high voltage direct current transmission cable insulation