[SOLVED] question about frequency conversion in transformers

[Uirani]

I have a question about transformers
A transformer with 60Hz works with 400Hz? Under what conditions?

and a transformer with 400 Hz works with 60 Hz?

- Why the tension must be reduced in proportion to the frequency?
- Why the kVA capacity is reduced by that amount?
- Why the copper losses are not reduced?
- Why do we have an increase in efficiency of transformer?

sorry but I am learning english yet...

 

[chuckey]

The effect of frequency on a transformer is tied to the quality of the "iron" used in its core. In years gone by valve amplifiers had transformers in them that were essentially flat from 30 HZ to 15 KHZ, its just they were big and very expensive!
using a 60 HZ transformer on 400HZ, the higher frequency will result in higher iron losses. Material becomes lossy when its magnetic flux is alternated at this higher frequency.
Using a 400 HZ transformer on 60 HZ. There will be insufficient inductance in the windings, so they will consume a lot of current (off load) which in turn will saturate the core (core becomes non-magnetic).
This is why the voltage must be reduced, to keep the current down. So KVA is down (same current , lower voltage). Copper losses = i^2 X R, same R, same i, r= resistance of windings.
Efficiency is up because iron loss is lower, - lower frequency.
Frank

 

[Uirani]

Ok, understood. Thank you very much for your reply!
But if using a 60Hz transformer on 400Hz and 400Hz on 60Hz even in the first case that we have higher losses and in second that we have insufficient indutance. It will work or not?

---------- Post added at 09:40 ---------- Previous post was at 08:01 ----------

I think that it will work with these restrictions. If you want to add some comments, feel free. Tonight I will mark as solved the thread.
Thanks!

 

[chuckey]

60 HZ on a 400Hz transformer will blow the fuse, so I guess it won't work.
400 HZ on a 60 HZ transformer would work but if the transformer was being run at its maximum, it would overheat and catch fire.
Frank