Great responses guys thanks!
things are gonna get a bit tingly if you brush against the wrong shiny bits on your inverter, might want to consider an isolation transformer
Yes - noted. Components will be housed in a steel box with explosion directing vents. I considered an isolation transformer - but decided to put my faith in the RCD powering the AC circuit instead... (it doesn't hurt that much - ask me how I know)
https://www.ebay.com/itm/362608870065?chn=ps&srsltid=AfmBOorqV9sS-TjzXmBYDbvp0canpjxWOre3GlLVky6TCtNknaUVnb4kQ24
its close. you can get 400V ones for a bit more. You don't need to get it new. its still going to kick the shit out some tricked out variac
https://alltest.net/categories/products/SGA400-12C-Sorensen
Thank you - I had not seen a Sorensen before - it is still out of my price range but I will keep an eye on the local classifieds in case someone is getting rid of one and doesn't know what they are worth!
what is the output ripple you are getting?
capacitors in that size are not cheap, did you buy new or used? they may not actually be 15mF
to get 340 volts you would need to reduce your 240vac down to about 200volts, then find where the PFC chip senses the actual output voltage and change the sense resistor. you can then get 340 volts out of it, regulated fairly well assuming you don't mess anything up.
a 3 ton board will easily handle the 2KW you need.
Thanks for your input.
I'm getting 6V P-P (modelled only as I am still trying to work out an NTC circuit to limit inrush to the capacitors).
The capacitors sure are 15mF @ 450V. Pic attached - they feel good and girthy to hold in the hand...
Regarding the 3-Ton board I need to be able to vary the output voltage and I am guessing they can only regulate to a single voltage level - what are your thoughts on that?
http://www.vias.org/crowhurstba/crowhurst_basic_audio_vol3_024.html
https://www.qsl.net/i0jx/supply.html
https://www.hammfg.com/electronics/transformers/rectifier
I think you should save up and buy a regulated modern DC power supply capable of the voltage. Car parts aint exactly cheap. IMO doing this with a variac and 45000uF of capacitance is dodge city. Its also going to be spectacular from a distance if you have a short circuit etc. A sorensen switching power supply will cut down on the madness.
Thank you for the links - as I understand a choke filter, it will limit the output DC voltage to 0.9 x AC RMS voltage - so that's a no go for me. Although when I tried to model a choke filter (as in the LTSpice file in my first post) it did not have that effect for some reason - so I am sure I have got somethign wrong in the LTSpice model.
I was thinking a 'PI' filter would achieve something similar to the choke filter, but wouldn't reduce the output voltage so much? (because the capacitor is 'before' the inductor so to speak). This is really what I am wanting to implement.
Thank you for pointing out the Sorensen, but as above its probably too much $$.
Any tips on adding an inductor to the mix, maybe in a PI configuration to smooth things over?