What is hysteresis?

This relates to the nature of transformers - generating magnetic flux. Permalloy coresuse this magnetic flux to induce a current in another coil. This hysteresis characteristic can cause energy losses in applications such as transformers. Therefore, “soft” magnetic materials with low hysteresis, such as silicon steel, are often used in cores instead of “hard” magnetic materials used for permanent magnets. Soft Iron Cores are able to enhance the magnetic field strength inside the transformer.

Then there is the issue of eddy current losses. Transformers typically have two coils wrapped around an iron core to form a complete ring. One of the coils is connected to the power source and is called the “primary coil”; the other coil powers the load and is called the “secondary coil.” Although often overlooked, Soft Magnetic materials and their related devices (such as inductors, transformers, and motors) play a key role in global energy conversion.

The conversion of electrical power involves the bidirectional flow of energy between source, storage and the grid, which is typically achieved through the use of power electronics. Electrical machines, including motors and generators, are able to convert mechanical energy into electrical energy and vice versa. The introduction of wide bandgap (WBG) semiconductors has enabled power conversion electronics and motor controllers to operate at higher frequencies. This reduces the size requirements for passive components in power electronics, such as inductors and capacitors, and enables more efficient, faster motors.

There are several soft magnetic materials that show promise for operating at high frequencies. As a type of oxide, soft ferrites stand out from other magnetic materials because they are insulating and therefore good at reducing losses caused by eddy currents.