DIY grid tie inverter - Project Status

[Tyler883]

General Status:

Early stages, ideas and  core direction not determined, yet.

Specifications and Features: W.I.P.

Due Date to lock in: not determined

Assigned Tasks:

Tyler - create a wishlist:study commercially available systems and create a list of features and specification (do not discriminate based on cost, feasibility,etc, yet)

[jacquesm]

hehe. So, it's official then.

Ok, as I said, I'm game. Whatever it takes.

The xantrex sw unit (or better) would be a lofty goal to shoot for, at the time it was the best on the market. Modular design would help a lot with being able to farm out pieces, but will make the final unit more expensive to produce. (but easier and cheaper to repair and upgrade)

For an example of a modular design see:
the outback unit. more info on www.outbackpower.com. I'd say right now they are at the head of the pack, but I don't have any personal experience with them, no doubt someone else here does.

it's pretty annoying that it takes a $5 part to turn 60A AC into DC but that it takes a $4K machine to do the reverse

[Tyler883]

Jacques,

Thank you, welcome aboard!

I would like to place the success of this project above and beyond my personal desire to be involved and learn. With this in mind,  I think a team effort of about 6-12 people would be awesome, even if that means that at some point I get pushed aside on some of the fun tasks.

Help wanted!

Regards

Tyler

[LEXX]

I would like to say that I, myself, am completely useless with this project!!  However I fully wish to use and abuse your hard work, so lots of very good luck to you.

LEXX

[bill541]

Just a quick note, I run an Outback inverter. It is an FX2548 48VDC, 2.5KW. And I agree with you, this is a much better inverter than the Trace SW series. In fact when Xantrex bought out Trace, Heart, and Statpower, a bunch of the sinewave engineers left and started Outback.

I havent really dug into the inner workings of the inverter,  but I know it uses a single transformer and is driven with MOSFETs by a PWM "Magic Sinewave" pulse train. The transformer steps up the voltage and removes the switching noise.

The Statpower Prosine series inverters use a large DC-DC converter to power a high voltage DC rail. They then use either IGBTs or FETS to do a direct synthesis of a 60Hz sinewave. They use a large Torroid filter at the output to remove the switching noise.

Both inverters produce a very clean output.

To keep it simple, maybe a modified sine would be better to start with.

Just some thoughts, Bill

[jacquesm]

I would not want to spend my time on modified sw, for the simple reason that I can buy for $49.95 what would take me $200 in parts...

I built a modified sw inverter when I was 16 (I didn't even know what to call it, just that it worked).

It's a funny story:

I lived in Amsterdam at the time, and my hobby was electronics, specifically building FM radio transmitters (slightly illegal). Conditions for connections where best at night, so I was up all night tring to reach 'Friesland', and sometimes even Germany. Or playing with my brand new 'Dragon' computer. And this played havoc with my school. So, my mom threatened to 'pull the plug' on me if I kept it up and one day she did.

I knew she would follow up on her threat so I was prepared: over the course of a few months I had stacked the roof of the building where I lived with old car batteries that I got from my neighbour called Leo (who was a garbage collector and got me all kinds of interesting stuff). A battery charger and a bunch of lamps were used to 'equalize' this makeshift pack (24 of them or so) into a useable 12 V battery bank that would last the night, a simple inverter made out of the transformer from a traffic light (don't ask where I got that one and two 2n3055's and a multivib took care of converting it back to 240.

So, one night the lights go off... flip switch... lights come back on.

Very confused mother is wondering whether or not she's gone totally crazy, she has the fuses in her hands and the lights are still on... you should have seen the look on her face.

Looking back with what I know now about electricity as contrasted with what I knew then this was a more than slightly risky setup. Imagine her putting the fuses back in WITHOUT coming up to see me first... that would have been quite the bang, chances are about 100% that 'my' power would be out of phase with the grid.

Or what would have happened if she had switched on the washing machine or an electric heater to see how much of this 'free' power was available.

Ah the good old times

[jasonweir]

I would love to help, not sure how much help I can be.  I'm not and EE or ME but willing to do what is needed.  Has anyone taken a look at this thread

http://www.fieldlines.com/story/2004/9/27/12627/6676

user ibedonc might be a good one to involve in this, it seems he already has a working inverter design, might be easier to modify this design then to reinvent the wheel..

Jason Weir

[jasonweir]

If this is going to be a serious project, I would suggest starting a project on

http://www.electronicprojects.org

I am willing to set it up and administer it, if this is something the powers that be would like let me know and I will take care of it...

Jason Weir

[jasonweir]

here is some more infomation at a 10KW grid tie inverter for under $500.

http://www.energychallenge.org/2001Reports/VT.pdf

Jason Weir

[Tyler883]

Hi

Just thought I'd check in so you guys don't think I've died or something.

I haven't had time to get back to this project. However, I have been reading other people's posts and projects. I've already looked at the inverter that ibedonc is making, and would like to learn more aboout it.

Work has been keeping me busy, I'm getting a chance to do some c++ programming to set up and control some test equipment.This is a chance for me to do some learning ( some of it on company time) so I'm not sure when I'll get back to this project.

cheers

Tyler