G10 fiberglass sheet used in dry transformer

To wind a transformer, we must have some knowledge of the materials related to the transformer, so here I will introduce the knowledge in this regard.

1. Iron core materials

The iron core materials used by transformers mainly include iron sheets, low silicon sheets and high silicon sheets. The addition of silicon into steel sheets can reduce the electrical conductivity and increase the resistivity of steel sheets. It can reduce eddy currents and reduce losses. The quality of the transformer is greatly related to the quality of the silicon steel sheet. The quality of the silicon steel sheet is usually expressed by the magnetic flux density B. Generally, the B value of black iron sheet is 6000-8000, that of low silicon sheet is 9000-11000, and that of high silicon sheet is 12,000-16000.

2. The material usually used for winding transformers

Enameled wire, gauze-wrapped wire, silk-wrapped wire, paper-wrapped wire are the most commonly used enameled wire. For the requirements of the conductor, it should have good conductive performance. Insulation paint has enough heat resistance, and must have a certain corrosion resistance. Under normal circumstances, it is best to use the QZ model of high strength polyester enameled wire.

3. Insulating materials

In the winding transformer, insulation materials shall be used for the isolation between the coils and the winding resistance. The general transformer frame materials can be made of phenolic paperboard, epoxy sheet like G10 epoxy resin fiberglass sheet or cardboard. The layers can be separated by polyester film, telephone paper, 6520 composite paper, etc. The winding can be separated by yellow wax cloth, or imine film.

4. Impregnating material

After the transformer is wound, there is the last process, which is the impregnated insulation paint. It can enhance the mechanical strength of the transformer, improve the insulation performance, and extend the service life. Under normal circumstances, cresol varnish can be used as the impregnated material or 1032 insulation paint, resin paint.