The Insulation Properties of Oil‐Impregnated Insulation Paper Reinforced with Nano‐TiO2

Oil‐impregnated insulation paper has been widely used in transformers because of its low cost and desirable physical and electrical properties. However, research to improve the insulation properties of oil‐impregnated insulation paper is rarely found. In this paper, nano‐TiO 2 was used to stick to the surface of cellulose which was used to make insulation paper. After oil‐impregnated insulation paper reinforced by nano‐TiO 2 was prepared, the tensile strength, breakdown strength, and dielectric properties of the oil‐impregnated insulation paper were investigated to determine whether the modified paper had a better insulation performance. The results show that there were no major changes in tensile strength, and the value of the breakdown strength was greatly improved from 51.13 kV/mm to 61.78 kV/mm. Also, the values of the relative dielectric constant, the dielectric loss, and conductivity declined. The discussion reveals that nano‐TiO 2 plays a major role in the phenomenon. Because of the existence of nano‐TiO 2 , the contact interface of cellulose and oil was changed, and a large number of shallow traps were produced. These shallow traps changed the insulation properties of oil‐impregnated insulation paper. The results show that the proposed solution offers a new method to improve the properties of oil‐impregnated insulation paper.