[RE-wrenches] Generator Controlled Mini Grid

[Glenn Burt]

Sounds like a job for a directional relay - utilities use them.

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Drake
Sent: Tuesday, February 12, 2013 7:29 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Generator Controlled Mini Grid

Hi Kevin,

Right now we are in the stages of investigating what is possible.  The
design is for 10kW of PV - inverter capacity.  The inverters will be Sunny
Boys, so if may be possible to regulate them.

We haven't decided on a generator yet.  A dump load sounds like a good way
to absorb excess power.

Have you heard of electronic controls to facilitate this process?

Thanks,

Drake


At 03:43 PM 2/12/2013, you wrote:
>Hi Drake,
>
>Further, can you give us an idea what scale you are talking here - ie 
>PV and Generator capacity? With your mention of inverter/generator if 
>your talking ie the small Honda EU6500 or such?
>
>I did think of another project that I am involved with - it's a remote 
>community with conventional diesel power plant (100 kW day,
>30 kW night). There is 27 kW of distributed PV over 5-6 different 
>homes, using the older Xantrex GT inverters. It's not the most 
>elegantly designed solution - as it's possible for PV output to be 
>greater than the load which causes shutdowns. In that case, a dump load 
>is kicked in briefly and that bumps the frequency enough to kick the GT 
>inverters offline, and then the cycle repeats.
>
>Not my design, but it does work and has been this way for several years
now.
>
>Kevin
>
>-----Original Message-----
>From: re-wrenches-bounces at lists.re-wrenches.org
>[mailto:re-wrenches-bounces at lists.re-wrenches.org]On Behalf Of Drake
>Sent: February 10, 2013 10:46 AM
>To: RE-wrenches
>Subject: Re: [RE-wrenches] Generator Controlled Mini Grid
>
>
>Hi Kevin,
>
>Thanks for the Eigg video.  What a great place.
>
>I didn't see evidence of any AC coupling of inverter produced AC to a 
>generator produced mini grid.  I understand this is being done in a 
>homebrew manner by some.
>
>The current wisdom on the issue is that the less the PV contribution to 
>the generator supplied grid is, the easier.  It would seem that if a 
>grid tie inverter output could be regulated, using Sunny Island type 
>controls, it should be possible to have a small inverter generator 
>create a mini grid that could be fed by PV.
>
>A system featuring this type of technology was linked in a posting on 
>this list some years ago, The link seems dead now.  In that case a 
>large generator was feeding a number of houses, and PV was fed into the 
>system.
>
>The reason for this interest is that battery backup systems are much 
>more expensive than generators.  We need to find a way to utilize PV 
>arrays during outages without the expense of battery backup systems.
>
>Drake
>
>
>At 07:42 PM 2/8/2013, you wrote:
> >Hi Drake,
> >
> >SMA has very good solutions for this. Does this out of the box 
> >without a bunch of custom control systems. I have put a few systems 
> >in like this, but the renewables not yet online (generator / battery 
> >now). If you google Isle of Eig you will find some info on what they 
> >have done there.
> >http://islandsgoinggreen.org/about/eigg-electric/
> >
> >Kevin
> >
> >-----Original Message-----
> >From: re-wrenches-bounces at lists.re-wrenches.org
> >[mailto:re-wrenches-bounces at lists.re-wrenches.org]On Behalf Of Drake
> >Sent: February 8, 2013 6:41 AM
> >To: RE-wrenches
> >Subject: [RE-wrenches] Generator Controlled Mini Grid
> >
> >
> >A potential customer is interested in a mini grid, set up by a 
> >generator, to connect his array to.
> >
> >Some years back, on this list, an article was linked about a 
> >community with a central generator that had PV input to the generator 
> >supplied, local grid, using electronic controls.
> >
> >Has any progress been made in this technology?  Does anyone have a 
> >link to the electronic control equipment or any other relevant
information?
> >
> >Thanks,
> >
> >Drake
> >
> >_______________________________________________
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> >
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