Abstract
Interests on ester liquids as replacement of mineral oil in large power transformers are growing in recent years. This paper presents experimental studies on streamer and breakdown in synthetic and natural esters. Lightning impulse voltage was chosen when considering the practicality of standard tests of transformer industry. First, streamer length, velocity, shape and mode were analyzed based on optical images obtained by a multi-channel ultra high speed camera. Under the same voltage level, streamer in both natural and synthetic esters propagates faster and further, with more branches, than in mineral oil. Breakdown tests at various gaps from 15 mm to 100 mm were conducted, and it was found that fast streamer led breakdown becomes statistically dominant in a large gap under lightning impulse and ester liquids have lower breakdown voltage than mineral oil due to their low tolerance to fast streamer. Therefore a relationship between the results under lightning impulse and previously published results under step voltage was built up and an empirical formula was obtained to predict the breakdown voltage of esters at very large gaps. © 2011 IEEE.
Original language | English |
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Article number | 5704520 |
Pages (from-to) | 285-294 |
Number of pages | 9 |
Journal | IEEE Transactions on Dielectrics and Electrical Insulation |
Volume | 18 |
Issue number | 1 |
DOIs | |
Publication status | Published - Feb 2011 |
Keywords
- breakdown
- insulating liquids
- lightning impulse
- natural ester
- Power transformer
- streamer propagation
- synthetic ester
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Dive into the research topics of 'Streamer characteristic and breakdown in synthetic and natural ester transformer liquids under standard lightning impulse voltage'. Together they form a unique fingerprint.Impacts
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Application of environmentally friendly and fire-safe transformer liquids
Zhongdong Wang (Participant) & Qiang Liu (Participant)
Impact: Economic, Environmental, Policy
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Reducing usage of fossil-oil-based insulating liquids in power transformers to deliver environmental, safety, and financial benefits.
Zhongdong Wang (Participant), Qiang Liu (Participant), Bangama Senasingha H Matharage (Participant) & Paul Jarman (Participant)
Impact: Society and culture, Economic, Policy, Environmental