1. Iron core material
The iron core materials used in transformers mainly include iron sheets, low silicon sheets, and high silicon sheets. Adding silicon to steel sheets can reduce their conductivity, increase their resistivity, reduce eddy currents, and reduce their losses. We usually refer to steel sheets with added silicon as silicon steel sheets. The quality of the silicon steel sheets used in transformers is closely related, and the quality of silicon steel sheets is usually represented by magnetic flux density B. Generally, the B value of black iron sheets is 6000-8000, low silicon sheets are 9000-11000, and high silicon sheets are 12000-16000.
2. The materials commonly used for winding transformers include
Enamel wire, sandbag wire, silk wire, the most commonly used enamel wire. The requirements for wires are good conductivity, sufficient heat resistance of the insulation paint layer, and certain corrosion resistance. In general, it is best to use high-strength polyester enameled wire of Q2 model.
3. Insulation materials
In winding transformers, insulation materials must be used for the isolation between the coil frame layers and the isolation between the winding resistances. Generally, the transformer frame material can be made of phenolic cardboard, the layers can be isolated with polyester film or telephone paper, and the winding resistances can be isolated with yellow wax cloth.
4. Impregnating material
After the transformer is wound, the final process is to impregnate the insulation paint, which can enhance the mechanical strength of the transformer, improve insulation performance, and extend its service life. Generally, cresol varnish can be used as the impregnating material.