The three-phase power transformer lamination core works in the AC state during the working process, and its power loss is not only in the resistance of the coil, but also in the iron core under the alternating current magnetization during the operation. Usually the power loss in the iron core is called "iron loss", and the iron loss is caused by two reasons, one is "hysteresis loss" and the other is "eddy current loss".
The hysteresis loss of the three-phase power transformer lamination core is the iron loss generated by the magnetic hysteresis during the magnetization process. The magnitude of this loss is proportional to the area enclosed by the hysteresis loop of the material. The hysteresis loop of silicon steel is narrow, and the core hysteresis loss of the transformer is small, which can greatly reduce the degree of heat generation.
There is an alternating current in the coil of the three-phase power transformer lamination core, and the magnetic flux generated by it is of course alternating. This varying magnetic flux produces an induced current in the core. The induced current generated in the iron core circulates in a plane perpendicular to the direction of the magnetic flux, so it is called eddy current. Eddy current losses also cause the core to heat up. In order to reduce the eddy current loss, the core of the transformer is laminated with silicon steel sheets insulated from each other, so that the eddy current flows through the narrow cross section to increase the resistance of the eddy current path, and at the same time, the silicon in the silicon steel makes The resistivity of the material increases and also acts to reduce eddy currents.