I would like to design a switched mode regulator (48 volt 40 amp battery) for my rov but i don't know how to do it or how it look like if i purchase it
So you looking at 50 amps combined total from the Battery if you have both motors going Thats a lot of current out of the battery Whats the amp hour on the Battery if you dont me asking
I recommend an off-the-shelf power supply. The reason is that a 2000 watt switching power supply is a major project and if you're like some of us you will go through a long and expensive learning process. And as reliability is probably paramount to your ROV, you don't want it failing.
If I understand, the input voltage is 48 volts. What voltage or voltages does the switching power supply need to deliver?
So a 10 volt 50 amp SMPS? That's a pretty hefty project. I'd look into buying one. Building your first SMPS is tough and expensive. Building your first SMPS with it being capable of delivering 500+W and 10A is even tougher and more expensive.
Id use nucluer power ( Only In marine subs I didnt say use as an energy souce on land did I , justin case lol ) If i was you
I can see you batteries going flat at about 300 below see level after about half an hour either that or once you open the ballast tanks you wont have enough air to blow them out to get to the surface again with that sort of current drain
The Linear Technology LTM8027 uModule regulator operates to 60 volts and outputs 4 amps. These devices can be paralleled to supply the 12 amp motors.
To account for differences output voltage tolerance a series resistor of perhaps 0.1 ohms is placed in series with each regulator. This should be optimized using LTSpice at which time the number of devices can be determined to provide >12 amps under worse-case conditions.
I think you would do best (save time and a steep learning curve) by going with an off-the-shelf solution. One solution I've used is the Vicor Maxi, Mini, Micro series of DC-DC converters.
For your 48-12 volt, 12 amp requirement the Vicor V48B12C250B will do the job. It will supply 12 volts at 21 amps and is $168 USD.
I agree with the off-the-shelf path. SMPS design and construction is not for beginners. Even though the switching frequency may not seem that high, the di/dt's are astronomical, and good PCB layout and overall construction is imperative if you want decent behavior out of it.