Device to adjust DC low voltage at 1500 amps

Ben,

for best voltage control an active circuit is the way to go. A series-pass element or a buck regulator can be used. To adjust 10 volts from 8-10 volts with a series-pass element at 1500 amps the power dissipation is up to 3000 watts. This is not a trivial amount power power to dissipate. A buck switching regulator can be built that will adjust a 10 volt source from 0-10 volts with a power dissipation of 500 to 1000 watts.

Are you serious you need 1500A at 10V? That is 15kW enough to power a whole neighborhood. For how much of time you need that.

We are going to use a stainless steel radiator with water circulating through it as coolant. We should be able to adjust the resistance enough by varying the length of actual pipe in the circuit. Apparently we used to do it alot but using it to control mulitple branch circuits has never been tried before.

We are heat rise testing power feed cables for conductor bars for a rail road line. So yeah, I'm serious. Voltage will probably be a lot less than 10V. Actually the 1500 amps is per conductor we are planning on running two simultaneous to speed up testing. SO that is 3000 amps at, if I were to hazard a wild guess, 2-5Vs.

So a super cap with 10000F would do. Get's you 3000A for 3 sec

We have to heat the cables up to there max temperature rating using there max free air ampacity. That's going to take longer than 3 seconds.

For this job it looks like AC will do the job. If that is so, an autotransformer feeding a step down transformer will do the job. This can be powered from single phase 240 VAC.

If DC is required the AC can be rectified. The best way to do this is a bridge rectifier and 3-phase AC.

DC is required. what you are proposing is that I build my own Power supply. But we already have a 5000A DC power supply, and a 10000A. Which are fed from 3 phase 480V. The problem is that we need to run the test on multiple devices simultaneously. In which case I need some way to balance the amperage across the multiple branch circuits. They all need to be at 1400A plus or minus 30A. The Ideal solution would be to buy 5 2000A DC power supplies but I don't have $40k to spend on the project.

So my solution to the problem is to just run two simultaneously but use stainless steel pipe that is water cooled as an adjustable resistor.

Is there a type of device that can adjust DC low voltage (.5 to 10 V) between 80% - 100% at 1500 amps? My boss (a Mech E) wants to use one power supply to heat rise test 5 samples simultaneously. So I need some ability to adjust the voltage some what on each of the 5 circuits. I assume some type of adjustable resistor would do the trick. problem is I'm not finding anything so far.

edit: Since people aren't ready the whole thread.

I need to cycle each of 10 DUTs 50 times. for a total of 500 cycles. Each cycle has to run until the device reaches it's max temperature rating which is 85C. we are guessing this will take about 45 minutes then it has to cool to ambient and the test repeats.

The solution I have come up with is to run just two simultaneously using stainless pipe with water flowing though it as an adjustable resistor.