The Study on the Influence of Electric Fields on Oil- Paper Griffin Curve

Moisture plays a crucial role in the aging and electrical strength of transformer oil-paper insulation. Currently, no sensor technology exists for directly measuring moisture content in transformer paper; instead, calculations rely on the Griffin curve for indirect assessments. This study explores how electric fields affect the moisture balance of oil-paper insulation at 80°C. The findings reveal that the electric field hinders moisture migration, and with increasing electric field strength, the moisture content in both oil and paper rises significantly. At 0 kV/mm, the results are consistent, while at 25 kV/mm, the average moisture content in the paper corresponding to the same moisture level in the oil increases by 32.92%. Moreover, macroscopic force analysis and microscopic molecular simulations further substantiate the experimental findings, offering insights for refining the moisture balance curve of oil-paper insulation under multi-physical field influences.