Saturation current of the coil inductor

We should all know a phenomenon. Add salt to a glass of water, and the salt will be slowly dissolved by water. When the amount of salt reaches a certain level, the salt will no longer dissolve in the water. That is to say, this cup of water has reached the salt that can be dissolved by itself at this moment. We say that the salt in this cup of water has reached "saturation". 
The various coils in which the inductor is wound with insulated wires are called inductors. An electronic component that is wound into one or more turns to produce a certain amount of self-inductance, often referred to as an inductive coil.

In the same way, when a current passes through the coil, a magnetic field is generated, and an increase in current in the coil will simultaneously increase the strength of the magnetic field, but this increase is not infinite. After the magnetic field in the magnetizer of the coil reaches a certain limit, the increase in current also does not increase the strength of the magnetic field. At this time, we also think that the coil and the salt in the water have reached the "saturated" state. We can call it "magnetic saturation", and the current intensity that can make this inductance reach magnetic saturation is considered to be The saturation current of the inductor.

The reason for the magnetic saturation of the inductor: the electrons rotate around the outer orbit of the atom. The electrons will generate a weak magnetic field during the rotation of each layer. The magnetic field of each layer is different, so the direction is different, but the role is The force is zero and there is no magnetism. When a coil is energized, a magnetic field is also generated. After the magnetic flux passes through the magnetic material, the electron begins to rotate, and the magnetic lines of force generated by the coil are eliminated. The coil current increases, and the magnetic material electrons change more in the direction of rotation. When the electronic rotation directions of the materials are the same, magnetic saturation occurs.

The factors affecting the magnetic saturation of the coil are: the larger the cross-sectional area of the magnetic path of the material, the smaller the current flowing, the smaller the number of turns of the coil, the less magnetically saturated; otherwise, the smaller the cross-sectional area of the magnetic path of the material, The larger the current flowing, the larger the number of coil turns, and the easier it is to achieve magnetic saturation. Therefore, the larger the power, the larger the volume (the magnetic circuit cross-sectional area is larger); the large current filter inductor has a large DC current, which is prone to magnetic saturation. In addition to the shape of the coil, an air gap is added to the magnetic circuit to increase the magnetic resistance and avoid magnetic saturation.