The silicon content of the EI Three Phase Lamination Core has little effect on the quality of the transformer, while the orientation and non-orientation are related to the type of the core. Secondly, even if the same type of iron core is not well processed, the quality difference is very large, and the difference is sometimes as high as 40%.
Good EI three-phase film core and the same material is very important for heat treatment and wire winding process. Good heat treatment can achieve 15000 Gauss with a small 10mA excitation current, and 50mA for poor heat treatment. The excitation current can reach the corresponding 15000 Gauss. Judging from the professional point of view, the core is good and bad, mainly through the excitation current, iron loss, saturation parameters of several indicators to carry out comprehensive prices.
Since the loss of the EI three-phase film core in the alternating magnetic field is small, the transformer mainly uses the EI three-phase film core as the magnetic material. Due to its high magnetic permeability and low loss, it is used to make transformers with the advantages of small size, light weight and high efficiency.
The EI three-phase film core is made by punching silicon steel sheets into E-type and I-type films of 0.35–0.5 mm thickness, and after heat treatment, they are inserted into the winding wire package, which is mostly made of hot-rolled silicon steel sheets. The cores of the ring-type and C-type transformers are formed by winding a cold-rolled silicon steel strip, wherein the C-type transformer is formed by heat-treating and varnishing.