9 Core Loss

Controlling transformer core loss is a priority, especially high-frequency transformers. Equation 2, the Steinmetz equation, shows the relationship between loss density in the core and frequency:

where P_FE is the loss per unit volume; ? is the excitation frequency; B_PK is the peak flux density in the core; k, α and β are material constants.

From Equation 2, it is apparent that as the frequency increases, so will the losses. The losses in modern magnetic materials start to become difficult to manage when the switching frequency goes much above 1 or 2 MHz.