FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W751082034> ?p ?o ?g. }

• W751082034 abstract "Mineral oil has been widely used in liquid insulation of power transformers. However, it is poorly biodegradable and could cause serious contamination to the environment if a spill occurs. With increasingly strict environmental rules and regulations, there is considerable interest from the Utilities to apply esters in power transformers as substitutions to mineral oil. In order to use esters in large power transformers, their dielectric properties should be thoroughly investigated. This PhD thesis covers the experimental studies on the dielectric properties of a type of synthetic ester (Midel 7131) and a type of natural ester (FR3) in both uniform and divergent electric fields, using a mineral oil (Gemini X) as the benchmark.The dielectric properties of transformer liquids in uniform fields were investigated using breakdown voltage tests. The breakdown voltages of esters should be at least similar to that of mineral oil to allow a replacement in transformers. To obtain a fair comparison, the AC breakdown voltages of well-processed transformer liquids were tested, and their distributions were statistically analyzed. Since the breakdowns of transformer liquids in uniform fields are caused by the weakest-links, conditions representative of in-service transformer liquids were also considered by testing the effects of extraneous factors, such as particles, water and electrode area.The divergent fields were produced by sharp needle electrodes with tip curvatures of a few micrometers. The dielectric properties of transformer liquids in such fields were studied using several methods. A traditional PD detector was used to study the partial discharge characteristics of insulating liquids, such as the inception voltages and the repetition rates. A high speed camera was utilized to identify the streamer generation, propagation and breakdown phenomena. An oscilloscope was used to investigate the current signals associated with these phenomena. The breakdown voltages of transformer liquids were also determined in the divergent field at various gaps. Furthermore, the fault gases in transformer liquids under partial discharge faults were determined and analyzed.The following findings and conclusions can be made from the research in this thesis:*The AC dielectric strengths of esters in uniform fields are similar to that of mineral oil when they are in a well-processed condition. When practical liquid conditions are considered, the AC dielectric strengths of esters are higher than that of mineral oil.*The partial discharge behaviours at overstressed voltages can be used to differentiate various transformer liquids. Esters are relatively inferior to mineral oil in terms of higher discharge amplitude, higher discharge repetition rate and more negative partial discharges.*Mineral oil possesses a higher ability to suppress the propagation of negative streamers. Thus, the AC dielectric strength of mineral oil in the divergent field is relatively higher than those of esters.*Esters generate the same types of fault gases due to electrical discharge as mineral oil, but in relatively larger amounts." @default.
• W751082034 created "2016-06-24" @default.
• W751082034 creator A5006822602 @default.
• W751082034 date "2011-11-10" @default.
• W751082034 modified "2023-09-23" @default.
• W751082034 title "Partial Discharge Behaviours and Breakdown Mechanisms of Ester Transformer Liquids under ac Stress" @default.
• W751082034 hasPublicationYear "2011" @default.
• W751082034 type Work @default.
• W751082034 sameAs 751082034 @default.
• W751082034 citedByCount "8" @default.
• W751082034 countsByYear W7510820342012 @default.
• W751082034 countsByYear W7510820342013 @default.
• W751082034 countsByYear W7510820342014 @default.
• W751082034 countsByYear W7510820342017 @default.
• W751082034 countsByYear W7510820342018 @default.
• W751082034 countsByYear W7510820342019 @default.
• W751082034 countsByYear W7510820342020 @default.
• W751082034 crossrefType "dissertation" @default.
• W751082034 hasAuthorship W751082034A5006822602 @default.
• W751082034 hasConcept C119321828 @default.
• W751082034 hasConcept C119599485 @default.
• W751082034 hasConcept C127413603 @default.
• W751082034 hasConcept C130143024 @default.
• W751082034 hasConcept C133386390 @default.
• W751082034 hasConcept C159985019 @default.
• W751082034 hasConcept C165801399 @default.
• W751082034 hasConcept C181335627 @default.
• W751082034 hasConcept C191897082 @default.
• W751082034 hasConcept C192562407 @default.
• W751082034 hasConcept C2779977313 @default.
• W751082034 hasConcept C49040817 @default.
• W751082034 hasConcept C66322947 @default.
• W751082034 hasConcept C70401718 @default.
• W751082034 hasConcept C78762247 @default.
• W751082034 hasConcept C80487561 @default.
• W751082034 hasConceptScore W751082034C119321828 @default.
• W751082034 hasConceptScore W751082034C119599485 @default.
• W751082034 hasConceptScore W751082034C127413603 @default.
• W751082034 hasConceptScore W751082034C130143024 @default.
• W751082034 hasConceptScore W751082034C133386390 @default.
• W751082034 hasConceptScore W751082034C159985019 @default.
• W751082034 hasConceptScore W751082034C165801399 @default.
• W751082034 hasConceptScore W751082034C181335627 @default.
• W751082034 hasConceptScore W751082034C191897082 @default.
• W751082034 hasConceptScore W751082034C192562407 @default.
• W751082034 hasConceptScore W751082034C2779977313 @default.
• W751082034 hasConceptScore W751082034C49040817 @default.
• W751082034 hasConceptScore W751082034C66322947 @default.
• W751082034 hasConceptScore W751082034C70401718 @default.
• W751082034 hasConceptScore W751082034C78762247 @default.
• W751082034 hasConceptScore W751082034C80487561 @default.
• W751082034 hasLocation W7510820341 @default.
• W751082034 hasOpenAccess W751082034 @default.
• W751082034 hasPrimaryLocation W7510820341 @default.
• W751082034 hasRelatedWork W2041855240 @default.
• W751082034 hasRelatedWork W2072130974 @default.
• W751082034 hasRelatedWork W2087284102 @default.
• W751082034 hasRelatedWork W2106420607 @default.
• W751082034 hasRelatedWork W2123518501 @default.
• W751082034 hasRelatedWork W2144617195 @default.
• W751082034 hasRelatedWork W2151383119 @default.
• W751082034 hasRelatedWork W2311466740 @default.
• W751082034 hasRelatedWork W2339373723 @default.
• W751082034 hasRelatedWork W2772564288 @default.
• W751082034 hasRelatedWork W2811332470 @default.
• W751082034 hasRelatedWork W2887206334 @default.
• W751082034 hasRelatedWork W2893567155 @default.
• W751082034 hasRelatedWork W2896717910 @default.
• W751082034 hasRelatedWork W3003834399 @default.
• W751082034 hasRelatedWork W3010196318 @default.
• W751082034 hasRelatedWork W3023345000 @default.
• W751082034 hasRelatedWork W3034646350 @default.
• W751082034 hasRelatedWork W3112220794 @default.
• W751082034 hasRelatedWork W806480403 @default.
• W751082034 isParatext "false" @default.
• W751082034 isRetracted "false" @default.
• W751082034 magId "751082034" @default.
• W751082034 workType "dissertation" @default.