2x1000 W SMPS for audio

[Sommer]

Hey all.
Im making my own 2000 W Power supply.
I need it to work with HD digital Audio.
So i want my switching frequency to be above 640 kHz.
Any of you who have made any SMPS with a frequency that high and a power output that high?
I cant figure out what topology to use.
Should i use the Full bridge, Half bridge, Quasi resonant or what?
Anything could be usefull

[Eva]

The operating frequency of the power supply has nothing to do with the sampling frequency of digital audio.

[AP2]

If you can, use a 2xHalf Bridge with trafo driver. fo=150-200Khz.(2x1000w)
in this way, you obtain clean and robust smps.obvious, that need good FB and filter output. this from my experience in psu.

Regards

[Sommer]

And the 150 - 200 kHz will not give so much EMI (or what is it called the noice)
that it will be visible on a 320 kHz samplerate signal.
Or will this need serious Shielding?

[savu]

make resonant mode half bridge smps and you will be ok with EMC.
for best results just encase the smps in a metal case. like a shield.

regards

[AP2]

Hi,
the emission (EMI) is significantly related to the shape of signals, especially in the case of square waves. The higher the speed, the harder it is to get clean forms. Many chip driver, producing a square wave with very fast rising edges but with spikes on the top and..other.
This greatly increases the emission of high harmonics. does not make sense to first create a lot of harmonics and then try to filter them.
is much better not to generate them.
You can use a driver chip (it is better if the inside is bjet with complementary, rather than mosfets), this chip can drive with a small transformer, the gate of the MOSFET. this option (because it has a lower band), ensures fewer high harmonics, if the circuit is well matched, the losses will be negligible and in part, can be gained from the transformer (if it's done right).
For the metal box, certainly a good solution, but some SMPS for audio that I have developed for company, have a very low emission (as you can see spectral analysis) and have no metal box.

Regards
Roberto P.

[ChocoHolic]

If you really want to go for such high switching frequencies, you will need
to go for a resonant or quasi resonant topology.
In hard switched solutions already 100kHz will show substantial switching losses, when heading for 2kW.
But also quasi resonant solutions may show the downside, that their soft switching is working just in a restricted power range.

There is no lunch for free.

P.S.: EMI hell is for free until they catch you.

[Eva]

The only way to go if such a high operating frequency is really mandatory (I seriously doubt) is to use several low power converters paralleled and advanced magnetics (magnetics laid out into the PCB), or to use several phases.

[ChocoHolic]

I tend to say that multiphase would be my favourite.
There are tons of three phase chips for motors/drives.
Good chances to find something that can be adopted for a multiphase DC supply.
And in case of a multiphase system, I do not think that you need to much specials.
The power requirements and the operating frequency of each power stage would decrease by factor three.

[Sommer]

Thank you very much everyone.
I have for now decided to make the Half bridge Quasi resonant converter.
Do some of you know where i can find any information about how to make the converter.
E.g. a homepage or a book. i have borrowed 7 different books but none says anything about how to make it.
more specs:
90 - 264 VAC input
50/60 Hz
output +- 50 VDC 20 A
Frequency 300 kHz to 1mHz or less if nessasary.
thats the requirements.