Effect of higher insulation material thermal conductivity on transformer temperature rise

摘要

Various types of solid insulation materials are used in the transformer design. While dielectric and mechanical properties of materials are the most important ones to consider in the transformer design, the thermal conductivity of material affects the temperature rise of transformers by determining the thermal resistance of heat transfer from conductor to the ambient. With the continuous new material development including nanocomposites, progresses were made to increase the thermal conductivity of insulation materials both at research labs and in commercial products. This type of development, however, could not be used in product design directly due to the lacking of understanding about how the increased thermal conductivity would benefit actual electrical equipment design such as transformers. Specifically, what is unclear is a quantitative understanding of the impact of higher insulation thermal conductivity on transformer temperature rises. In this study, the topic was addressed from simulations based on thermal network modelling. The effect of increased solid insulation thermal conductivity on transformer temperature rises was studied with different transformer types including liquid filled transformer and dry type transformer, transformer rating, winding type and designs. Several conclusions have been drawn from the study for practical guidance on transformer design using solid insulation materials with higher thermal conductivity.