If it was me I would be tempted to run the power up as a higher voltage DC and do the step down with an off the shelf SMPS or two to get the 24 volts and 40 amps output.

TCMTech - based on your suggestion, can two (or three) rectified DC outputs be put into series to increase the voltage to 780 VDC or higher? Is there a simulator that can be used to test some theories? Thanks!

 

with proper isolation transformer usage, you could series connect DC power supply outputs to add voltages. I would be scared shitless of a cobbled together set of 10-20 power supplies with more than 500 volts sitting on the top of it.

 

Theoretically you could run 110VAC at 5A through a 22 gauge wire. Why not just run the AC to the distant point and then a 24V SMPS at the distant point? The 5A comes from a look at input needs for a 3A, 24VDC switcher. But this is theoretical, it never would meet code, but neither would 500VAC through the same small gauge wire.

 

TCMTech - based on your suggestion, can two (or three) rectified DC outputs be put into series to increase the voltage to 780 VDC or higher? Is there a simulator that can be used to test some theories? Thanks!

yes they can provided each has some degree isolation from the input to the output.

I would recomend that if you are going much over 400 volts to split the power into two halves with the common center point tied to ground.

So if you are running near 800 volts make one as a +400 in reference to ground and the other -400 in reference to ground. The reason being that when you are running conductors high up into the air they have some sort of earth ground as part of the system to drain off the static charges that will build up.

 

I purchased a 600V to 120/240V transformer to test with. Carefully connecting it in reverse to get 600v (or a bit less with drop) out of it, would I connect 240v to X2 and X3? Thanks!

 

This is why it scares the (blank) out of us to coach people with lethal voltages.
Read the label.
The label says 600 volts are on H1 and H2.
The label says the 240 volt wires go on X-1 and X-4
The label says X-2 is connected to X-3 for a 240 volt hook up.

 

Thank you and do understand your concern. That is how I read it and was responsible enough to hold off on making any connections until getting further info on the process.

 

I hope you will use metal containers for the switching and the fuses. 3KW at 600 RMS is enough to sustain its own arc and/or blow you to Heaven.