The reason for this is that the sheet laminated core can reduce another type of iron loss – eddy current loss.
In a transformer, the coil generates alternating current, and the magnetic flux it generates is also alternating. The changing flux induces a current in the core. Known as eddy currents, the induced current generated in the core circulates in a plane perpendicular to the direction of the magnetic flux. The core is also heated by eddy current losses. The core of the transformer is stacked with laminated steel sheets that are insulated from each other in order to reduce eddy current loss. By increasing the resistance on the eddy current path through a smaller cross-section; Additionally, laminated also reduces eddy currents while increasing the material’s resistivity. The core of the transformer is generally made from cold-rolled laminated steel sheets with a thickness of 0.35 mm, which are cut into long pieces, then overlapped into a “日” or “口” shape. According to theory, the narrower the spliced strips are, the better the effect of reducing the eddy current when the laminated steel sheet is thinner. By reducing eddy current loss and temperature rise, laminated steel sheets are also saved and eddy current loss is reduced.
Why laminated coats are used in transformer?
Transformer cores are generally made from laminated steel sheets. Steel containing silicon (also called silicon) has a laminated content ranging from 0.8 to 4.8%. Due to its magnetic properties, laminated steel is a magnetic material with superior magnetic permeability. In the energized coil, laminated steel can generate a large magnetic induction intensity, which can lead to a reduction in transformer volume. Transformers operate in AC mode, and power loss occurs not only in the coil’s resistance, but also in the magnetized iron core. There are two reasons for the power loss in the core, a hysteresis loss and an eddy current loss. Iron loss due to hysteresis during magnetization of the core is proportional to the size of the hysteresis loop around the core. Laminated steel has a narrow hysteresis loop, while the core of the transformer has a small hysteresis loss, which can greatly reduce heat generation.
