What core for a 1Kw fuel cell inverter

[Spanner66]

Hi Guys,

I need to build a 1Kw buck converter to stableize the varying output of a hydrogen fuel cell to give a 24V output.

I have found what looks to be a good circuit using the Linear Technology LT1339 chip.

All the parts on the design note sheet are availiable but I am unsure about what core to use for the 10uH 50A inductor.

Any help would be greatly appreciated.

Many thanks.

 

[Ubergeek63]

you don't really want to wind that thing, do you?

Use 4 of these in a series parallel combination:
https://www.electro-tech-online.com/custompdfs/2009/01/4935b080-1881-43db-b73d-e2176f2c5e73.pdf

Besides, you won't be able to get the core with out paying through the nose or being a manufacturer that can reasonably be expected to use it in the future.

Dan

 

[Blueteeth]

I understand the convenience for using a Buck converter, but, for 200W+ I would think about a half bridge converter, possibly forward, as the efficiency can be higher. Transformers though, are obviously less appealing to the builder over inductors

For a 1kW Synchronous Buck converter, you're looking at a maximum of 90% (ish) efficiency, which means a maximum of 100W to disappate somewhere. Of course, 'Linear Tech' do make some of the best DC/DC converter controllers, but for such high power...its a tough project.

Also, you could parallel several MOSFET/inductors, like a 3 phase Buck converter seen on PC motherboards. The current now days can reach 30A on those....albeit with very low value inductors (400nH). I would spend the cash on a premade inductor....I'm sure there's nothing like winding your own but at that current, it'll be tough..even with big litzwire.

Let us know of your progress!

Blueteeth

 

[ronsimpson]

Coil Craft SER2914 series, use two in parallel or series.
Try BI they have about the same thing.
JW Miller 2300ht-100
Coiltronics CTX10-16-52
EPCOS Inc B82559A7103A25
Try Pulse Eng they have some nice coils.
All these above are 1/2 what you need but you could use two.

 

[Spanner66]

Many thanks guys, you have been a huge help.

I will buy some wound inductors, I did not really want to wind my own, just could not find any with anything like enough current carrying capacity.

I will let you know how I get on.

Paul.

 

[ronsimpson]

What frequency are you switching at?
What type of wire will you use?