Why is my transformer humming?
A transformer that hums isn't necessarily defective. An electrical transformer naturally produces a slight hum when it's operating. The laminations in the magnetic circuit expand and contract very slightly…
In modern electrical networks, harmonics are increasingly present, especially with the generalization of electronic equipment and converters. At Le Cosinus, a French manufacturer of electrical transformers since 1954, we support our customers in understanding and controlling these disturbances.
What is a harmonic?
Harmonics are multiple sinusoidal components of the fundamental frequency of the lattice (50 Hz or 60 Hz). They are generated by nonlinear loads such as variable speed drives, switching power supplies, or certain industrial equipment.
The effects of harmonics on the electrical transformer
La présence d’harmoniques dans un réseau impacte directement le fonctionnement et la durée de vie des transformateurs. Les impacts sont les suivants :
- La Surchauffe du transformateur : Les harmoniques provoquent une augmentation des pertes fer et cuivre par courant de foucault, générant un échauffement supplémentaire non négligeable du transformateur.
Transformer decommissioning, which involves using a transformer at a lower load than it was designed for (or taking a more powerful transformer), is not a solution. Indeed, this will have a moderate impact on copper losses, but none on iron losses. The iron will continue to overheat.
- Accelerated aging, temperature rise, and additional stresses reduce the life of insulators and windings.
- Voltage distortions, harmonics degrade the quality of the output voltage, which will no longer be perfectly sinusoidal, which can disrupt the connected equipment.
How does Le Cosinus set up its electrical transformers in the face of harmonics?
At Le Cosinus, we design and manufacture standard and custom-made transformers, capable of withstanding environments disturbed by harmonics:
To do this, we can act on several parameters:
- The use of materials and conductive sections adjusted to limit losses.
- Adapt the electromagnetic induction of transformers to limit the heating linked to iron losses.
- Integration of control sockets to adapt the induction of the transformer.
We are able to apply these adaptations to all our transformers at all frequencies (50 Hz, 60 Hz, 400 Hz and more) and also to specific applications such as wavetrain or phase angle dimmers for example.
Conclusion
Harmonics represent a major technical challenge to guarantee the performance of transformers, the efficiency, durability and reliability of electrical installations over time. Thanks to nearly 80 years of expertise, Le Cosinus supports manufacturers and electricians with adapted, reliable and sustainable solutions.
Need a harmonic-resistant transformer?
Contact us and entrust us with your specifications: we will offer you the solution best suited to your needs.
