FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W16987138> ?p ?o ?g. }

• W16987138 abstract "The health of the transmission power transformers in the power system networks is critical to the reliability of electricity supply. Knowing the precise life expectancy of the transmission power transformer is of vital importance as it permits an optimised asset replacement. The traditionally regarded transmission power transformer?s life expectancy of 40 years is considered dated for the transformers in the UK according to the transformer life data in 2010. In this thesis, it is aimed to investigate the life expectancy of the transmission power transformer in the UK from three aspects: statistical analysis on historic transformer life data, thermal modelling of in-service transformers, and through the in-service transformers? furan measurements.A detailed statistical analysis shows that deriving the transformer?s reliability at a certain age by calculating the hazard rate is inadequate, as the hazard rate at each age has a statistical range in which the confidence band width is related to the amount of the reliability data. The transformer life data in all ages are grouped together to derive a general hazard rate of 0.27%. It is concluded that the transformer life expectancy could not be derived via statistical approaches due to the limited data available at the older transformer ages.As an alternative approach, regarding the life of insulating paper as the ultimate life of a transformer, the thermal model published by the IEC transformer loading guide 60076-7 is reviewed and extended to estimate a transformer?s thermal lifetime. The model is improved in two aspects, such that Arrhenius equation is adopted to consider the paper?s practical ageing mechanism of oxidation and hydrolysis when calculating the paper?s ageing rate; and the model takes consideration of the paper?s moisture accumulation effect.The developed thermal model is used to reversely derive the generally unknown model input ? hot-spot factor, by the means of regarding the scrapped transformer?s degree of polymerisation (DP) predicted thermal lives as a benchmark. Assigning the derived hot-spot factor to the field units with regard to the design family, the thermal lives of 106 in-service transformers have been estimated. To enlarge the life sample, the modelling lives are combined with the 79 scrapped transformers? DP predicted thermal lives. The thermal life expectancy, defined as the median life of the sample set, is derived as 88 years. A series of sensitivity studies are performed to examine the derived life expectancy?s responses on the variations of load, winding-to-oil gradient, top-oil temperature rise, and the setting of winding temperature indicator.As a non-intrusive approach in transformer?s insulating paper assessment, the correlations between the 2-furaldehyde (2FAL) concentration dissolved in transformer oil and paper?s DP derived by different laboratories are reviewed which are found to differ significantly. As a first-time attempt to derive the 2FAL-DP correlation relationship for the field transformers, the paper?s DP is estimated at the age when oil was sampled using the thermal model, and is plotted with the 2FAL measurement. De Pablo?s equation is found to fit the plot of the DP estimates against the 2FAL measurements better than other function formats. The 2FAL concentrations corresponding to the paper?s critical DP levels are given using the developed 2FAL-DP correlation relationship." @default.
• W16987138 created "2016-06-24" @default.
• W16987138 creator A5004585346 @default.
• W16987138 date "2013-02-14" @default.
• W16987138 modified "2023-09-24" @default.
• W16987138 title "Life expectancy investigation of transmission power transformers" @default.
• W16987138 hasPublicationYear "2013" @default.
• W16987138 type Work @default.
• W16987138 sameAs 16987138 @default.
• W16987138 citedByCount "1" @default.
• W16987138 countsByYear W169871382015 @default.
• W16987138 crossrefType "dissertation" @default.
• W16987138 hasAuthorship W16987138A5004585346 @default.
• W16987138 hasConcept C119599485 @default.
• W16987138 hasConcept C121332964 @default.
• W16987138 hasConcept C127413603 @default.
• W16987138 hasConcept C133925201 @default.
• W16987138 hasConcept C144024400 @default.
• W16987138 hasConcept C149923435 @default.
• W16987138 hasConcept C163258240 @default.
• W16987138 hasConcept C165801399 @default.
• W16987138 hasConcept C200601418 @default.
• W16987138 hasConcept C2908647359 @default.
• W16987138 hasConcept C62520636 @default.
• W16987138 hasConcept C66322947 @default.
• W16987138 hasConcept C92018576 @default.
• W16987138 hasConceptScore W16987138C119599485 @default.
• W16987138 hasConceptScore W16987138C121332964 @default.
• W16987138 hasConceptScore W16987138C127413603 @default.
• W16987138 hasConceptScore W16987138C133925201 @default.
• W16987138 hasConceptScore W16987138C144024400 @default.
• W16987138 hasConceptScore W16987138C149923435 @default.
• W16987138 hasConceptScore W16987138C163258240 @default.
• W16987138 hasConceptScore W16987138C165801399 @default.
• W16987138 hasConceptScore W16987138C200601418 @default.
• W16987138 hasConceptScore W16987138C2908647359 @default.
• W16987138 hasConceptScore W16987138C62520636 @default.
• W16987138 hasConceptScore W16987138C66322947 @default.
• W16987138 hasConceptScore W16987138C92018576 @default.
• W16987138 hasLocation W169871381 @default.
• W16987138 hasOpenAccess W16987138 @default.
• W16987138 hasPrimaryLocation W169871381 @default.
• W16987138 hasRelatedWork W135399620 @default.
• W16987138 hasRelatedWork W1527768402 @default.
• W16987138 hasRelatedWork W2001941562 @default.
• W16987138 hasRelatedWork W2043032216 @default.
• W16987138 hasRelatedWork W2046724302 @default.
• W16987138 hasRelatedWork W2046916664 @default.
• W16987138 hasRelatedWork W2113856444 @default.
• W16987138 hasRelatedWork W2171567616 @default.
• W16987138 hasRelatedWork W2291498353 @default.
• W16987138 hasRelatedWork W2352074358 @default.
• W16987138 hasRelatedWork W2387203937 @default.
• W16987138 hasRelatedWork W2942888662 @default.
• W16987138 hasRelatedWork W2964927043 @default.
• W16987138 hasRelatedWork W3007432115 @default.
• W16987138 hasRelatedWork W3013693505 @default.
• W16987138 hasRelatedWork W3109231369 @default.
• W16987138 hasRelatedWork W3204954769 @default.
• W16987138 hasRelatedWork W132391540 @default.
• W16987138 hasRelatedWork W2186254823 @default.
• W16987138 hasRelatedWork W3145037817 @default.
• W16987138 isParatext "false" @default.
• W16987138 isRetracted "false" @default.
• W16987138 magId "16987138" @default.
• W16987138 workType "dissertation" @default.