Moisture and Aging Effect on the Creepage Discharge Characteristics at the Oil/Transformer-board Interface under Divergent Field

The creepage discharge on pressboard barriers is regarded as one of the failure modes for power transformers. In literature, extensive research has been carried out previously to investigate the nature of creepage discharges, while little work was done to study the creepage discharge on the aged transformer board. A literature survey will be given first to summarise the understanding of creepage discharges on cellulose/oil interfaces. The effects of the aging products like moisture and absorbed sediments on the characteristics of creepage discharges will be investigated.