You can trick some grid-tied inverters into working in "island" mode by providing an AC signal from a smaller 'off-grid' inverter.
The trick, however, is controlling the power output. Most grid tied inverters want to work in an all-or-nothing mode, if they were tied to a DC source that doesn't sag under full load, they would try to output their max power, whether you need it or not. If the load can't take the full output, then the voltage climbs above the cutoff threshold and they shutdown. I've been thinking along these lines myself and I think a better alternative might be to use DC-DC converters to convert the pack voltage down to 24-48V and use a more typical off-grid inverter. July 29, 2020 8:58 AM, "Robert Bruninga via EV" <[email protected]> wrote: > If you can find an off-grid inverter with 300 VDC input then I sure want to > know about it! Really... that is the holy grail... > All off-grid inverets I see are designed for 48 volts for compatibility > with batteries. > You only see 300-500 VDC input on Grid inverters since there are no > batteries. > > Bob > > On Wed, Jul 29, 2020 at 12:50 AM Luke Scharf <[email protected]> > wrote: > >> Thanks! I've managed to find https://plugoutpower.com and read through >> their site. I'll contact them if I have something they might find >> interesting. >> >> I just purchased a GM 2-mode hybrid pickup truck, and have been doing >> pen-and-paper design exercises to see if adding an electric power takeoff >> inverter is possible. >> >> It looks doable. Figuring out how to tap into the HVDC system under the >> hood doesn't look that hard, and finding electrically-compatible parts >> (such as an off-grid MPPT inverter which can take a 300VDC input) also >> looks fairly doable. >> >> But, plugging things together is the easy part. There are a lot of >> engineering constraints and safety/durability issues which would need to be >> thought through carefully. This is a pen-and-paper design exercise for me >> for now. >> >> -Luke >> >> On Sun, Jul 26, 2020, 11:34 AM Robert Bruninga <[email protected]> wrote: >> >>> There is a company (called Plugout I think) working on a 3kw and 5kw >>> version but best I can tell, they are taking the simple way out. They are >>> just taking a normal inverter (designed for HVDC input for Europe (220 >>> VAC) and then selling you an autotransformer to convert to split phase 240 >>> VAC. >>> >>> But the weight of a 3 to 5 kW autotransfomer has got to be hundreds of >>> lbs. And price goes up to the thousands. >>> >>> To me it should be a designers dream and huge market, EXCEPT that it will >>> require professional hacking to each EV or Hybrid model depending on >>> voltage and how hard it is to get access to the HV circuits. The prius >>> battery was 220 VDC and pretty easy to get to. No one seems to know how to >>> get into a Volt's battery without dropping the entire battery from below. >>> >>> Bob, WB4APR >>> Author ARRL: http://aprs.org/Energy-Choices.html >>> >>> On Sat, Jul 25, 2020 at 11:40 PM Luke Scharf via EV <[email protected]> >>> wrote: >> >> Has anyone done anything like Richard Factor's PriUPS, except with the GM >> 2-Mode hybrid? >> >> Thanks, >> -Luke >> >> On Sat, Jul 25, 2020 at 3:25 PM Lee Hart via EV <[email protected]> >> wrote: >> >>> redscooter via EV wrote: >>>> I want to do a prius 12vdc battery to 120 vac invertor. which of the >>> prius >>>> can do this meaning, turn the car on, turn off all the extra loads, >> turn >>>> on invertor. Which years or gen /s will stay on and keep charging >> the 12 >>>> vdc battery?? some talked about using the manal key to lock the >> doors. >>> >>> I have a 2001 Prius, and my son has a 2014 Prius. We really don't have >>> to do anything special to power an inverter. Just leave the key "on" >>> with the car in "ready", and the ICE will start and stop as necessary >> to >>> keep the 12v battery charged. >>> >>> Small inverters (under 100w) can be plugged into the 12v accessory >>> outlet. Larger ones should be connected directly to the battery with >>> heavy wires, as they can draw a significant amount of current. >>> >>> Bob Bruninga has done a significant amount of work on Prius with >>> inverters. Check out his website for details and ideas >>> <http://www.aprs.org/aprs-swer.html>. He's on this list, so perhaps >>> he'll chime in with more information. :-) >>> >>> Lee Hart >>> >>> -- >>> If happiness is on your mind, here's a daily list to find: >>> - something to do >>> - something to look forward to >>> - someone to love >>> - someone to take good care of >>> - and misbehave, just a little >>> -- >>> Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com >>> _______________________________________________ >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >>> ARCHIVE: http://www.evdl.org/archive/index.html >>> INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org >>> Please discuss EV drag racing at NEDRA ( >>> http://groups.yahoo.com/group/NEDRA) >>> >>> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: < >> http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200725/6d61d58b/attachment.html >>> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> ARCHIVE: http://www.evdl.org/archive/index.html >> INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> Please discuss EV drag racing at NEDRA ( >> http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200729/158fa882/attachment.html> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
