Thermal stability of insulating material is the main factor affecting the service life and overload capacity of oil-immersed transformer. The high temperature solid insulating material which can be used in oil-immersed transformer is described in terms of preparation technology, physical and chemical properties, electrical properties and anti-aging ability. The application of high temperature insulating material in oil-immersed transformer is put forward. The problems that need to be paid attention to.

Oil-immersed transformer has the characteristics of good heat dissipation, low loss, large capacity and low cost. It has become the most widely used power transformer in power grid. Its reliability is directly related to the safety and stability of power grid. Oil-immersed transformer adopts solid-liquid composite insulation structure. At present, conventional oil-paper insulation system composed of cellulose insulating paper and mineral insulating oil is often used. Safety and reliability of insulation system is the basic condition for normal operation of transformer. During the operation of oil-immersed transformer, insulation system will gradually aging due to the influence of temperature, oxygen, moisture and many other factors, among which thermal aging is the most important one. Thermal stability of insulating material is the main factor affecting the capacity and volume of oil-immersed transformer. According to GB/Z 1094.14-2011, the solid or liquid insulating materials of mineral insulating oil of heat-resistant supercellulose insulating paper are high temperature insulating materials. Different insulating materials can be combined to form different heat-resistant registered insulating systems. Win by selecting different heat-resistant grade insulating materials according to different temperature requirements, taking into account insulating materials. The heat resistance and economy of the material.

Scholars at home and abroad have done a lot of research on high temperature insulation materials for oil-immersed transformers. In the field of solid insulation materials, on the one hand, aromatic polyamide paper and polyamide adhesive paper have been applied in oil-immersed transformers. On the other hand, the application of polymer materials in oil-immersed transformers has attracted official attention, such as polyester, polycarbonate and so on. Improving the aging resistance and heat resistance of insulation materials for oil-immersed transformers is still an important part of the development of insulation materials.