Transformer core EI lamination three phase why should be coated with insulating paint

- Apr 13, 2019-

The transformer core EI lamination three phase constitutes the magnetic circuit of the transformer, and at the same time plays the skeleton role of the body. The transformer core is generally formed by laminating a 0.35 mm thick, surface-coated insulating varnish. Since the silicon steel sheet itself is also an electric conductor, an induced current is also generated in the core under the action of the AC magnetic flux.

If the transformer core EI lamination three phase is not coated with insulating varnish, the core will become a whole, which is equivalent to a large-area conductor, and its resistance value is small. Although the induced voltage is not high, the induced current is large. This produces extreme eddy current (circulation) losses. In severe cases, it will cause iron core heat and even rust to melt, which is called iron core "fire." 

After the insulation paint is applied between each piece, the core is divided into a plurality of small-section conductors. Thus, the vortex pump resistance becomes larger. Painted iron cores, although there are also eddy current losses (part of the iron loss), are much smaller. Transformer core EI lamination three phase insulating paint thickness is generally only a few microns, so you do not have to worry about whether his thickness will affect everyone's normal use, but if there is no such obstacle, then everyone will use it in the process I found that the effect could not be achieved at all.