What are the insulating materials of Liquid-filled transformers?

The main insulating materials inside Liquid-filled transformers are transformer oil, insulating cardboard, cable paper, telephone paper, and crepe paper. Here are some detailed explanations of Liquid-filled transformers insulating materials.

This is the content list:

Insulating cardboard

Cable paper

Phone paper

Crepe paper

Insulating cardboard

Liquid-filled transformers insulating paperboard are mainly made by pressing unbleached sulfate fibers, and there are a lot of pores between the fibers. Therefore, Liquid-filled transformers insulating paperboard has strong air permeability, oil absorption, water absorption, etc. If the Liquid-filled transformers insulating paperboard uses polyamide fiber paper with higher heat resistance, the service life is greatly improved.

Cable paper

Liquid-filled transformers cable paper is a kind of insulating paper, made of kraft pulp. In Liquid-filled transformers, DL2-08 and DL2-12 cable papers are used, with thicknesses of 0.08mm and 0.12mm. It is mainly used for the insulation of the outer surface of the Liquid-filled transformers and the interlayer insulation of the coils, and the insulation of the lead wires. It is one of the main insulation materials of the Liquid-filled transformers.

Phone paper

Liquid-filled transformers phone paper is made of kraft pulp. Telephone paper is used in Liquid-filled transformers. Its thickness is (0.5±5%) mm, and it is rolled into a paper roll with a width of (500±10) mm. Liquid-filled transformers are mainly used for coil wire insulation and coil end insulation.

Crepe paper

Liquid-filled transformers crepe paper is also a kind of insulating paper. It is reprocessed from cable paper made of sulfate pulp. It has very good electrical properties in oil, which is characterized by high average breakdown voltage and tangent of the dielectric loss angle. The value is small. Liquid-filled transformers crepe paper is mainly used for wrapping transformer outlets.

It should be noted that the dielectric coefficient ε of Liquid-filled transformers insulating paper and cardboard is more than 4 to 2 times the dielectric coefficient of transformer oil ε=2.2. Under the action of the electric field of Liquid-filled transformers, the field strength shared by the Liquid-filled transformer's composite insulating material is inversely proportional to the dielectric coefficient of the material. It can be seen that the field strength in the coil gap of Liquid-filled transformers is much stronger than that of Liquid-filled transformers cardboard, so the oil gap becomes the weak link of the Liquid-filled transformer's oil-paper insulation. When the dielectric coefficient between them is close, the size of the insulating structure of Liquid-filled transformers can be reduced. Therefore, a new type of Liquid-filled transformers paperboard with a low dielectric coefficient is the current research and development direction.

Zhejiang Shuntong Electric Co., Ltd. is a professional manufacturing enterprise integrating development, production, sales, and service. The company was established in 2009 and is located in Liushi Town, "China's Power Capital", specializing in the production of various high and low voltage equipment. The above is about the relevant content of Liquid-filled transformers insulation materials. If you are interested in Liquid-filled transformers, you can contact us. Our website is www.sntoom.com. We look forward to your visit and hope to cooperate with you.