Max DC current for chokes
I'm having trouble finding high current and high inductance DC chokes. This is why I'm asking you this question about the max DC current for a choke.
If a choke can handle 200Amp DC current, does that mean that it can handle any waveform as long as it has an average value of 200Amps?
Thanks!
No. Strictly spoken, there's a RMS current rating (calculated according to known scheme) and a saturation current. The saturation limit counts for instantaneous current. In addition, high AC currents (ripple current) might cause extra skin effect and core losses that must be considered by a derating.
What's "high inductance" for you?
Hello
Thanks for answering this fast.
The DC choke I'm looking for is around 200Amp and 0.5mH (more is better).
The signal I should be using is a rectified signal having an average value of 200Amp
I shouldn't worry about skin effect since I have low frequency harmonics
So high inductance is something around 0.5mH (for this current rating).
Thanks
For a size estimation http://www.emb-wittlich.com/ENGLISCH...ten/GD-GDS.HTM
Resulting weight is 26 kg.
Hello.
I didn't get any update about the subject.
Do I have to choose an inductor using the DC current, the rms and the max? The saturation current should be equal to the max current. Am I right?
An inductor designed for 200 A will have a certain margin for current ripple, so it will usually work for 200 A average with superimposed ripple. Also a low or medium ripple won't increase the total RMS current much.
The should be a L = f(I) saturation curve that allows to decide about acceptable peak current for your application.
Thanks a lot Mr FvM
I asked this question because my peak current can reach something like 300Amp, and this is not a small ripple.
I will ask inductor companies for these curves and hope to get them .
Again, thanks a lot for your help. Much appreciated