I would like to build a switched-mode DC-to-DC converter which should support up to 4000 W of power. It should be able to act as a CCCV power-supply, so supply a constant current Imax up to the point where voltage Vmax is required to have that current, and then supply a constant voltage Vmax with a diminishing current.
I would like it to be modular, to be able to swap-out a few components to change the Imax and Vmax. I do not want to have knobs to change the Imax and Vmax like on a general-purpose lab power supply, as these parameters will be changed very rarely, when I change the battery configurations, maybe every few months, and I do not want the risk of me or someone else accidentally turning the knobs, and then connecting it to the batteries with wrong parameters which could kill very costly batteries - as I want this to support up to 4kW, you can imagine the batteries will be large. No, I don't have batteries supporting such current yet, but within years I could have, so I want this device to be easily expandable as my battery park grows.
EDIT - I modified my expectations, which I hope will make it easier to build:
The configuration I would like to have:
- Input: rectified 230VAC mains (that will be something around 325VDC?)
- Output: CCCV with exactly Imax=15.0A, Vmax=230.4VDC
- input and output electrically isolated
- low ripple (1% is OK, 2.5% is too much)
- efficiency at least 90%, I am willing to spend up to 10% more for every extra 1% efficiency that I gain over 90%.
In the future I would like to be able to install modules to be able to accept a different voltage input, for example from solar panels, so a design that will accept a wide voltage input range (say 100-400VDC) would be a plus.
I would be grateful for some basic pointers into how to build such a beast, possibly using some ready-made blocks, but I don't want to buy the whole device, as I want it to be modular and expandable (unless some DIY kit is available).
I could take four Chinese 48V (adjustable to 58.8V) 15A CCCV supplies for less then 200$ each and connect them in series to do the job, but then I have "black boxes" which if a single component inside brakes, not having the schematic will be difficult to fix. So I would prefer to spend even twice as much for a modular, self-made design, so if something breaks I can easily exchange the faulty element, and if my desired voltages change I can just rebuild part of the device without buying a whole new one.