Does anyone make a 1000vdc single phase inverter? Would reduce wire costs dramatically
Jay Peltz power. > On Sep 18, 2018, at 11:36 AM, Lorenzo Ortiz <lore...@cal-solar.com> wrote: > > Thanks for all the input guys. After looking at the 3 phase with transformer > options with some transformer manufacturers, that has been pretty much ruled > out due to complexity/cost. > With single phase step-up and step-down transformers, even at 600VAC, it > still requires some monster wire. > The best solution seems to be placing the inverters next to the POI and just > running long strings from the array back to the inverters and accepting up to > 4%-5% voltage drop. And that's with #8 instead of the usual #10 AND > accounting for worst-case production. > > Man, sometimes this solar stuff is just crazy... > >> On Tue, Sep 18, 2018 at 10:15 AM, Blake Gleason <bl...@sunlightandpower.com> >> wrote: >> Good advice already on this thread. A couple of points to consider: >> >> 1. Re: step-up/step-down option (probably what I'd do): definitely pay >> attention to transformer spec to minimize both magnetization and operating >> losses. Newer DOE 2016-compliant transformers are MUCH better than before, >> and that's just the minimum standard. If you really want to minimize >> magnetization losses, you can always design a relay/timer to disconnect the >> transformers at night (from the interconnection side), although I've found >> that this setup is either very expensive or too unreliable (nuisance >> tripping upon re-connect, timer gets "off" cycle somehow, etc). >> >> 2. I think someone mentioned a 480V single-phase inverter. I'm not aware of >> a high-quality product meeting that description. Is there one? All of the >> "480V" single-phase inverters I'm aware of are 277V (line to neutral), which >> is hardly worth the transformer effort (versus 240V). >> >> 3. Definitely use aluminum wire for the long run. If wire size is still too >> large, even with step up/down tranformers, consider allowing slightly >> increased voltage drop at full power (say, 5%), and, depending on typical >> grid voltage at the site, change taps on one of the transformers to err on >> the low side (from inverters' point-of-view), to keep the inverters from >> tripping at upper voltage limit at full power (max voltage drop/rise). >> >> >> Blake >> >>> On Tue, Sep 18, 2018 at 9:57 AM, Jerry Shafer <jerrysgarag...@gmail.com> >>> wrote: >>> Lorenzo >>> You might want to look at relocating the inverter(s) closer to the meter >>> instead of the array, one reason is even if there is some line loss at full >>> power its less as the voltage goes up and the inverter does not see the >>> line resistance that can cause high voltage issues at the inverter. Some >>> engineers use more side of peak performance than full power, this keeps >>> wite size down and does not effect output >>> Jerry >>> >>> On Sep 17, 2018 9:42 AM, "Lorenzo Ortiz" <lore...@cal-solar.com> wrote: >>> Wrenches, >>> >>> We have a PV array situated about 900' from the POI (240V 1PH). We >>> initially spec'd (5) 11.4kW inverters and the combined output would be >>> 238A. The wire size required for this current over that distance is cost >>> prohibitive. >>> >>> A solution was to use a single 50kW 3 phase inverter at the array and then >>> convert it to 240V... somehow? Is anyone familiar with how to go about >>> doing this? My thought was to have a step down transformer at the POI and >>> pull off two legs to get 240V. Is this even a thing? >>> >>> The other, more expensive option is to use a step up transformer at the >>> array and a step down at the POI to get us a smaller wire size. >>> >>> Thanks for any input. >>> >>> >>> -- >>> Loren Ortiz Commercial PV Designer >>> >>> lo...@cal-solar.com (530) 274-3671 >>> >>> >>> >>> >>> Showroom located at: 149 E Main St. Grass Valley, CA 95945 >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> List Address: RE-wrenches@lists.re-wrenches.org >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >>> >>> >>> >>> _______________________________________________ >>> List sponsored by Redwood Alliance >>> >>> List Address: RE-wrenches@lists.re-wrenches.org >>> >>> Change listserver email address & settings: >>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >>> >>> List-Archive: >>> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >>> >>> List rules & etiquette: >>> www.re-wrenches.org/etiquette.htm >>> >>> Check out or update participant bios: >>> www.members.re-wrenches.org >>> >>> >> >> >> >> -- >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> Blake Gleason - PE, LEED AP >> Director of Innovation & Technical Excellence >> >> P: 510.845.2997 x128 >> E: bl...@sunlightandpower.com >> W: sunlightandpower.com >> >> See how universities are using business as a force for good with solar! >> >> _______________________________________________ >> List sponsored by Redwood Alliance >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Change listserver email address & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out or update participant bios: >> www.members.re-wrenches.org >> >> > > > > -- > Loren Ortiz Commercial PV Designer > > lo...@cal-solar.com (530) 274-3671 > > > > > Showroom located at: 149 E Main St. Grass Valley, CA 95945 > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org >
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