User-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:68.0) Gecko/20100101 Thunderbird/68.4.1
I'm looking at alternatives for powering a medium sized coil/coils. I'm
thinking in the 10kVA and up range.
I think I would like three phase power 240V from 10-25 kVA (I think), so
I can do a simple rectifier for a DC bus.
If I went to a single phase supply, I'd need filter capacitors with
largeish stored energy. 8 milliseconds at 20 kVA is 160 Joules which is
0.8 uF at 20kV. Doable, but bulky. (not that a three phase transformer
isn't heavy, but...)
So here are some alternatives
Run off single phase 240V at home (40A@240V is just 10kVA), rotary phase
converter (which would be big.. something like a 15HP three phase motor)
Buy a generator that puts out 3phase. New towables around 10kVA are
around $10k, but maybe you can get a used one significantly cheaper?
(assuming it hasn't been horribly abused, e.g. by some dude running a
tesla coil with no HV suppression on the power line - more likely, some
dude running it without changing the oil or without oil at all)
You can get a fixed generator that's 25kVA (e.g. generac 25kVA 3 phase,
120/208) for $9k (but then I'd have to buy a trailer to move it around)
- hmm maybe buy a cheap used pickup truck and mount it in the bed? A
self propelled tesla coil system?
Rent a generator that puts out 3phase (kind of a hassle to go down and
rent the generator every time I want to experiment, but maybe it works.
$260/day, $600/week, $1700/mo)
Buy a collection of single phase generators that are lashed together and
somehow synchronized (yeah, that's TCML hackery... ) 10 kVA (ish)
generators are about $1000 on Amazon (e.g. Westinghouse dual fuel 9500)
or a Harbor Freight for $800-900. Yeah, they're noisy, inefficient, but
my usage duty cycle would be low.
Speaking of synchronization, what about ganging up inverter generators.
I've ganged two Hondas together but that was single phase. I think you
could built a small phase shifter box, or a small rotary converter
(something like a 1HP three phase motor) and gang three inverter gens
together. I'd be a bit afraid of cooking the electronics with a TC.
There's something robust about using technology that was matured 100
years ago when Tesla and Westinghouse were still alive.