DC/AC Inverter for Off-Grid Solar Station

You may not find this easily. PVPowered could possible fabricate this. The DC input from the batteries being above 50V would require the NEC Chapter 480 t0 be applied. 480 says this must have restricted access and meet greater safety precautions. 48V nominal is commonly found as the input to most PV power centers (inverter/rectifiers). Switch to a 48V nominal. Use multiple Outback Flex80's in tandem to govern your batteries

Check wih Victron Energy Systems in Holland they may have something in their off grid product equipment

Excellent advice!

Check with American Superconductor (www.amsc.com).

That is some Big & Bad inverter!! If it was 100% effective, you would be talking about 250 amps......probably nearer 300 amps at 12 volts with an average effective unit.....that will have to be some battery(s) to supply that for more than a few minutes or so.....

Are you certain you need that much power, if yes, buy a diesel generator!! it will be cheaper than buying the correct batteries.....I mean - don't try using car batteries for this job.....

build one your self, ther is a lott of chematics on the www to work with.

At that current!!!! Please show me such a link!!! I am disbelieving though.....

It is slightly possible I suppose......I've been wrong before, I am sure it will happen again....

Andy, It's 3KVA at 200 - 400VDC supply

OK. ...and your point was?

I was asking for a circuit diagram for a "real powerfull" DIY version, somewhwere on the web ( a guest said it was possible to find)......but I really do not believe that its possible....but FULLY prepared to be wrong if need be.....as ever!!

I certainly would not even try to make one of that sort of power......the small DIY ones are dangerous enough!!

Sorry, just could not resist the temptation

WOW!!!!

Well "found", but "where" did you find it, I need a readable copy (if its for real!!)

Are you certain it is only 3000 VA? That is a small system. Why do you want to run it at 200-400VDC? It presents an excessive danger for the application. As suggested above by other respondants, a safer <48VDC would require about 100A peak capacity when the DC is at its lower value. This is easier to find in commercially available inverters / UPS.

If you meant 3000 KVA, send me an email, this is real power electronics, we can help you.

Marco

Why not using a normal VFD for electric motors in your application ?

Is you disable the input rectifier and connect a DC voltage (230 x sqrt 2) to the capacitors, you can get a variabel AC voltage at the output.

Why would you want to build one? For 170 quid ($250) you can buy one! Making an inverter is simple. Making a reliable inverter is another story.

You will need to wind a transformer because the ratio required is not a standard 230V:12+12. Getting a 3kVA transformer to start with will probably cost you near this sum. Protection against shot circuits, overloads, overheat and inductive spikes will all be neccesary if you want your device to run for a usable time.

This came out on the top line of a search...ebay.

Hey Cap Blanc, Are you set up as a Victron dealer as yet? noticed yesterday that their 100 amp chargers are now set up as universal input including 400 V DC presumably for their off grid PV installations. And they now have a 5000 watt inverter which can be parallelled for huge outputs.

Considering the original request was for 230V 50 HZ I would guess the poster is looking at an installation outside the US of A and therefore NEC does not necessarily apply.Might be in your area of the world. You guys are doing some really great PV projects over there.

Hyperion belonging to Jim Clarke is getting a refit with something like a dozen victron inverters plus a few chargers. From the pictures it looks to be wired as 3 phase at somewhere around 50KVA power levels.

Do you have any better info on their off grid systems?

You wrote: we are just re-configuring a system of 400 down to 24V. There was a NZ company called Santon who made freq converters which were really UPSs. These had banks of 385V(nom) at about 200Ah. These were about the same era as the Helionetics converters from California.:

So is this a case of dated technology and the latest thinking being 200V - 400V DC is not such a good idea. Back in the early nineties I worked at a power transformer station and we had 200 V DC back up in case the grid went down totally. The DC battery bank would allow us to operate the switch gear and get the power transformer station back on line. We always considered the battery room one of the most hazardous places in the station to perform work in.

Too bad the original poster was a 'guest' We will never know if this thread is being seen by the OP. Sounds like Helionetics is a company with a product that fits the OP's original request criteria