I am connecting a Kohler 12RES to my house, the roof has 3.1KW of PV connected to a SB3000. I thought we would have problems so we all knew to turn of the solar before turning on the generator. One day, we forgot, and it all worked. Since that I have left the solar on each time we ran the generator. As we are in a small island, power outages are common. The Kohler has a problem I cannot get to the bottom of and I'm going to pull a Generac from inventory and install it, so I will find out if that also works. My home and office is a test lab, I'll try anything there.
On Mon, Feb 11, 2013 at 8:44 AM, Drake <drake.chamber...@redwoodalliance.org > wrote: > Chris, > > It sounds like you are creating a generator supplied mini grid, if I > understand correctly, My reading is that your generator is creating the AC > voltage, and the inverter is synchronizing with it, allowing power to be > fed into the system from a PV source. > > This approach could represent a major innovation in solar industry. I > remember a decade or so ago when it was proposed, on this list, that > battery based inverters could be backfed to charge batteries, and someone > tried it. It worked. Today AC coupling is standard operating procedure. > > Up to that time, it was only understood that to connect an AC source to > the output of a battery based inverter could damage it. Maybe the next > step is to AC couple to generator supplied sub panels and allow PV usage > during power outages. > > What inverter and generator are you using? How many Watts of PV are > connected? > > Thank you, > > Drake > > > > At 02:04 PM 2/10/2013, you wrote: > > I have a generator and PV system that just works together, despite all the > dire predictions that it won't. from my experience of PV and generators (I > am also a generator tech), the biggest issue is the AVR board and how it > responds to back fed voltage, and the generator controller's over voltage > settings. > I think that it would probably on only require a reprogrammed inverter to > make this work as follows. > The AVR produces excitation voltage to vary the strength of the rotor > field and therefore the induced voltage in the stator. When the PV system > back feeds the generator, the excitation level is reduced to control the > voltage. When there is no load, the inverter keeps raising the voltage to > attempt to push the current to the grid and at some point the generator > trips out on overvoltage. > > If the inverter was programmed to reduce the production of power in > response to the rise in voltage, it would sync pretty nicely with the > generator. However, this would likely violate the IEEE parameters for a > grid tied inverter. SMA has off-grid mode, I suspect that is the best > solution. > > In a Sunny Island system, as I understand it, the Sunny Island caries the > frequency to communicate to the inverter to reduce the current output. That > avoid the problem of the inverter raising the voltage. > > > > > On Sun, Feb 10, 2013 at 2:45 PM, Drake <drake.chamber...@redwoodalliance.org> > wrote: > 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-boun...@lists.re-wrenches.org > [ > mailto:re-wrenches-boun...@lists.re-wrenches.org<re-wrenches-boun...@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 > > _______________________________________________ > List sponsored by Home Power magazine > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > > > -- > Chris Mason > President, Comet Systems Ltd > www.cometenergysystems.com > Cell: 264.235.5670 > Skype: netconcepts > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > -- Chris Mason President, Comet Systems Ltd www.cometenergysystems.com Cell: 264.235.5670 Skype: netconcepts
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