Amorphous cores – also known as metallic glass cores – are made from a rapidly cooled metal alloy with a disordered atomic structure. They reduce a transformer’s no-load losses by up to 70 percent compared with conventional grain-oriented steel cores, making them a key technology for sustainable energy infrastructure. As pressure grows for higher efficiency across the entire distribution grid, amorphous cores are increasingly becoming the standard for modern distribution transformers.
Why are amorphous cores so efficient?
Unlike crystalline electrical steel, amorphous metals have no ordered atomic structure. This metallic glass structure results in very low hysteresis losses and high electrical resistivity, which reduces eddy current losses. Amorphous cores are produced by extremely rapid cooling of liquid metal, preventing the formation of a crystal lattice. The resulting thin ribbons are processed into cores and used primarily in modern distribution transformers.
Key Characteristics at a Glance
- Up to 70% lower no-load losses compared with conventional electrical steel
- Particularly efficient in moderately loaded distribution transformers
- Meets the highest Ecodesign requirements (EU 548/2014 Tier 2)
- Service life of 40+ years with no significant loss of efficiency
- Higher acquisition costs pay off over the operating life
- Ribbon thickness typically 0.02 to 0.03 mm
- Multi-layer structure achieved through winding technology
Frequently Asked Questions
Is the use of amorphous cores economically worthwhile?
For distribution transformers permanently connected to the grid with moderate loading, the higher acquisition costs are often recovered within 5 to 10 years. Over the total service life of 30 to 40 years, this results in substantial savings in energy consumption and CO₂ footprint – a clear economic advantage.
Where are amorphous cores typically used?
Primarily in distribution transformers of the 10 to 36 kV voltage classes with ratings from 25 kVA to 3,150 kVA. They are also gaining importance in BESS applications and photovoltaic parks, where loading fluctuates significantly over time and no-load losses carry particular weight.
Are there any disadvantages compared with conventional cores?
Amorphous cores are noisier under magnetic saturation, more mechanically sensitive, and more complex to manufacture. However, these issues are offset through careful design. For very large power transformers, their use is still limited by the available ribbon widths.
How are amorphous cores handled in manufacturing?
Amorphous ribbons are extremely thin and mechanically sensitive, requiring specialized winding and processing machinery. Careful process control prevents mechanical stress and preserves the core’s excellent magnetic properties over its entire service life.
How are amorphous cores processed in the workshop?
Because the ribbons are thin and brittle, special winding machines with precise tension control are used. Processing requires particular care, as mechanical stresses can impair the magnetic properties. After winding, the core is heat-treated to relieve internal stresses.
Are you planning to use highly efficient transformers with amorphous cores? Our specialists will advise you on cost-effectiveness, Ecodesign compliance, and the right sizing – get in touch with us.