Hi everyone,

Firstly, thank you for your time out to read this post.

I'm looking to make a very high power voltage regulator, DC to DC.
I am finding it almost impossible to find a ready made off the shelf product that meets my specs as the output voltage level is not standard these days. An old AVR (Automatic Voltage Regulator) has now failed but the voltage level is not standard anymore to find a replacement.

Required specs are as follows:
Required stable Output: 90VDC, 150A max === 13.5kW.

At the moment I only know that the input voltage source is DC where it will need regulating to the above output specs.

Lets just suppose for now that the Vin Max would be 110VDC.

Can anyone please advise me on where I may be able to get a schematic to design such a regulator? I'm very aware that these are dangerous levels to be working with.

Any advice anyone can give me would be greatly appreciated.

For anyone who is wondering, the AVR I need is for a railway locomotive, hence the high power specs. I am part of a volunteer railway preservation team.

Thank you again for your time and I look forward to any advice you can give me.

 

It's probably going to require a switch mode rather than linear converter - a linear regulator would need to shed 3kW of heat at full load. If you can't source or don't want to build a single high power converter you might consider parallel operation of several lower power modules (which might be available off-the-shelf).

Parallel operation to boost total current is reasonable practice.

See http://cdn.vicorpower.com/documents/application_notes/vichip_appnote16.pdf

 

Building a 13.5 KW buck regulator is no easy task. Inductors aren't cheap either, you are looking at about 5-8 pounds of ferrite and a few pounds of copper for a lower frequency fail safe design, and a non trivial amount of capacitors for the input and output.
But this also depends on what efficiency you consider to be a minimum, and the output voltage regulation you need, if you don't need a real clean output, then you don't need to over design it, just something to reduce the voltage.

I would reccommend you build several, as in 6 or more, buck regulators in parallel, with the "phases" synchronized, this reduced the input and output voltage and current ripple.

however, if this is a motor controller, then it gets quite a bit simpler, and i would recommend buying one off the shelf, though they may be hard to find.
http://www.cafeelectric.com/shop/index.php?main_page=index&cPath=1
Zilla is in the process of moving their manufacturing location, but their converters will handle a quarter megawatt, there are some still available here http://www.evcomponents.com/ProductDetails.asp?ProductCode=Z1K-LV

 

In addition to the Zilla motor controller (which is excellent quality but has had availability problems), I know of a team in Portland, Oregon that's building DC motor controllers that will easily handle your voltage and current. Check www.synkromotive.com for details. (I'm friends with the proprietors and have seen their product in action, but I have no financial interest in making this recommendation.)