High-power High-frequency Transformers

Applications and material selection

Listed applications are high-power switching power supplies, inverter DC motor systems, electrolysis/electroplating supplies, laser supplies, communications supplies and high-frequency induction-heating supplies.

The brochure states that silicon steel is unsuitable above 15KHz. Ferrite offers low high-frequency loss but relatively low saturation flux density, resulting in a larger/heavier core and less efficient circuit-board space use; its lower Curie temperature is also described as limiting thermal stability.

Nanocrystalline material is described as combining high flux density, high permeability, low losses and temperature stability for inverter transformer cores.

Brochure material comparisons

Nanocrystalline saturation flux density is stated as three times that of ferrite. A same-volume core is described as providing twice the output power of ferrite and greater overload capability.

At 15KHz–50KHz, core loss is stated as 1/2–1/5 of ferrite loss. Permeability is described as over ten times ferrite, reducing excitation power and copper loss. The iron-based nanocrystalline alloy Curie temperature is printed 570oC, described as three times that of ferrite.