Commonly used transformer cores are generally made of silicon steel sheets. Silicon steel is a kind of silicon (silicon also known as bismuth) steel with a silicon content of 0.8 to 4.8%. The core of the transformer made of silicon steel is because silicon steel itself is a magnetic material with strong magnetic permeability. In the energized coil, it can generate a large magnetic induction intensity, which can reduce the volume of the transformer.
We know that the actual transformer always works in the AC state, and the power loss is not only in the resistance of the coil but also in the core under the alternating current magnetization. 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".
Hysteresis loss is the iron loss caused by the hysteresis phenomenon in the magnetization process of the iron core. 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.