Assessing the condition of Nomex paper-based Insulation in Open Wound and VPI type Dry-type Transformer using Frequency Domain Spectroscopy Data

摘要

Dry-type transformers are becoming increasingly popular in urban areas due to its non-flammable properties. Being air-cooled, such units require less installation space compared to their counterpart Oil Impregnated Paper (OIP) having the same power rating. Open Wound types of dry-type transformer insulation like Dip-Bake type or Vacuum Pressure Impregnation (VPI) are popular and are being used extensively for constructing distribution transformers. Nomex paper is usually considered as the main insulation for such dry-type transformer insulation. The present paper describes the effect of thermal aging of Dip -Bake type and VPI type dry-type transformer insulation samples constructed in the laboratory. At the end of thermal aging, Frequency Domain Spectroscopy (FDS) data for both the dry type construction is recorded and compared.