I have a few upcoming projects that will require some higher power battery applications where voltage swing needs to be limited. Both will be powering electric motors.
The first on will be ~1.3-1.5 kW, 24 V motor (7s21700 battery). The second will be a 10 kW, 72 V (20s21700 battery) motor. So the 4.2-2.5 V swing per cell is going to put me outside my acceptable voltage range on both projects.
I could limit the charge/discharge voltages but that would just suck because I don’t want to lose that storage. So the obvious theoretical answer is a buck/boost converter.
Practically speaking though I have never designed a 150 A buck/boost converter. I played around with some sims without much hope and was met with a rather unreasonable set of components (do they exist? Sure, but I would like to not have to sell a kidney to build this thing).
I have searched around for a few night but I haven’t found anything of real value. So thats the background.
A: Am I missing some pretty obvious solution here?
B: If not, is a DC/DC converter of that size feasible (space for cooling isn’t a big issue)?
C: If it is feasible, any pointers? It's definitely going to be trickier than a little 2-3 A one.
One last thing: the reason I need the voltage to be pretty constant is because these will be used in marine applications where variation in power output directly affects the handling.