Why does the AC inductance of the primary winding decrease after the transformer core flux is saturated?

- Sep 07, 2020-

First of all, understand what is inductive resistance, which is both simple and complex. Inductive reactance is the size of the hindering effect of inductive load on current

We can analyze the influence of inductive reactance on current from a microscopic point of view

When the current in the coil increases, it will excite the magnetic field in the core to become stronger, which will generate a back electromotive force and hinder the current from becoming larger. When the core is saturated, the current continues to increase, but the magnetic field cannot continue to become stronger, which leads to The back electromotive force is too small, and the hindering effect on the current is weakened or even invalid. At this moment, from a macro point of view, the current changing current of the winding has become larger, that is, ΔI/Δt has become larger, which means that the hindering effect on the current has become smaller.

-----Back to the definition of inductive resistance, that is, the inductive resistance has become smaller