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Forum Index : Electronics : Hybrid inverter experiences?
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| Godoh Guru  Joined: 26/09/2020 Location: AustraliaPosts: 458 |
I am about to add another 4kw of panels to my off grid system. I am considering using a hybrid inverter, instead of buying lots of MPPT controllers to connect to the battery. I would want an inverter capable of about 4kw continuous to charge the car on sunny days. Also battery voltage is 24 volt. And to make things more difficult I want to keep my DC panel voltage below 120 volts, so that it is legal for me to do the work myself. Does anyone here have experience with hybrid inverters that would do the job. I see plenty of cheap ones on Ebay that work on paper, but some real life experience from other folk would be great Pete |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1352 |
Hi Pete I'm in the same boat as you on 24 volts and I don't plan on changing that in the future mainly as when I finally get my 4Kw motor conversion in the air it is wound for 24 volts and i aint taking the rotor out to rewind again. Now I made my first inverter for just over $100 using a 3Kw toroid from a aerosharp Wiseguy got me for $25  and I got a 2Kw inverter board from ali for $84 delivered. I made my own dual choke using the big choke out of the aerosharp and to my surprise when I did a test using 2 vacuums which was 3.4Kw load both turned on and just worked. So the next step was my Unimig Viper 182 amp mig welder with flx wire and it worked nicely.Now for the MTTP's grab some of the boards from here and make your own and by making your own if something goes wrong you can fix it apposed to spending $1,500 on a MTTP then finding with a problem it's scrap. Mate don't be scared to start and in the end it will be worth all the fuss and i'm sure you will never look back. Cheers Bryan |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Thanks Bryan, I do have one MPPT board, but have not started it as I have not yet got my head around all the stuff on the site about them. It seems that they are a work in progress, and the parts seem expensive. Especially the Hall effect chips. I would need to build at least 3 of them. I have built a couple of my own inverters using powerjack transformers that I have rewound, and 8010 boards from aliexpress and they work well. What I want is to be able to get at least 3600 watts from a 24 volt inverter, that way I can use a 15 amp charger to charge the car. My home made inverters and my Latronics ones are 3kw. So the Hybrid inverters seem like a good way to go, as they can run directly off the panels and charge batteries when not inverting. I will dig the MPPT board our one day and have a look, though there are some parts that are not marked on the board and that makes stuff more complicated. Cheers Pete |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1027 |
Depends on your definition of Hybrid inverter, its sort of changed a bit over the years. The way the batteryless inverters work, they use the solar to supply the loads with the assistance of the grid, in your case the grid would be your shed inverter, they can have batteries as well same as any offgrid inverter, unfortunately I never seen one in 24v and they are always high voltage solar input 500v orso, not what you want. So I Think you will be building yourself a charge controller or 2 or 3  Cheers Aaron Off The Grid |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Hi Aaron, this is the sort of inverter I am looking at. One plus is this mob actually put a name on their inverters and produce a manual. That is pretty rare for chinese knockoffs. https://www.ebay.com.au/itm/155826067252?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20230823115209%26meid%3Da72d88c66cf94c67a3825c261fa23d4a%26pid%3D101800%26rk%3D1%26rkt%3D1%26sd%3D155826067252%26itm%3D155826067252%26pmt%3D1%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2SignedOut%26brand%3DPowMr&_trksid=p4375194.c101800.m5481&_trkparms=parentrq%3A2a89cc6018d0acda33c9c5b1fffca2ea%7Cpageci%3Aba5d7d13-b81f-11ee-bc16-6278592d6241%7Ciid%3A1%7Cvlpname%3Avlp_homepage It says in the specs that MPPT starts at 55 volts and goes up to 450 volts. I am hoping that means the inverter will be fine with about 75 volts from the panels. I am interested in what folks here think Pete |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1027 |
First I have seen in 24v, not the most reliable type, but they are a cheap quick solution..... sometimes. Says the MPPT is 120v-500v wide voltage range so I doubt your panel voltage will be enough, you could ask coulomb, he would know a little bit about these types, different brand though. If Solar/Utility mode works as it says, then it could also be fed from your other inverter as well. Cheers Aaron Off The Grid |
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wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156 |
I tried to find information about this unit for interest & stumbled across this review which is somewhat less than 100% satisfied. His application was a 48V unit but the 24V one might be cut from the same cloth.... The review isHere Hope you end up finding something suitable. If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1027 |
Yes its hard to tell what your getting these days with all the knockoffs, I have the older 48v model made by Voltronic, started with that one back in 2015, at the moment I have 3 running today, each one has no load idle of 50w, they each have the low voltage charge controllers built in, not using them now, and you cannot buy these older HS or MS units anymore, too many knockoffs. This is why I always intended to build our own, not far off replacing these Voltronic inverters now.  Footnote added 2024-01-22 12:15 by Revlac Looks like the genuine one is the PIP-4024MT 4000w 24v MPP Solar inverter high PV DUAL AC output WIFI, seems to have programmable AC out time? Cheers Aaron Off The Grid |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Hi Bryan, I did get a set of boards for an MPPT 150 volt 50 amp charger. I am not sure who I got them from now, it was a long time back. The boards look different to the ones I saw on your build. I think the ones I have require 2 nano chips. So have not got around to building them as it is too difficult for my skill level to get my head around. I have built plenty of kit things over the years, but they come with clear instructions, I also made three 8010 inverters but they are mostly built too. Unfortunately after trying to read all the pages on the MPPT controllers here, I am just getting more confused. I do not have programming with Nano skills either, so that makes stuff harder. I will keep reading and see if I can up my skill level thanks pete |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 651 |
Hi Pete, You got those MPPT boards from me. The second nano chip was required for me to be able to use a display I had in my parts box. That is all it does, drive my display. If you use the display Poida suggested you won't need that second nano. Building electronic projects is relatively easy for me, should be easy-ish for you too with your electrical back ground. There are no SMD parts on that board I'm no good with programming either, got a friend to do that. Maybe poida could ship you a programmed nano, should not cost much posting wise. The most tricky part of that MPPT project was the calibration, eventually got my head around the programmer speak instructions, then it was straight forward. If you can source suitable second hand capacitors (from broken GTI's) then you safe a fair bit on parts cost. |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Thanks Rev, I have most of the parts required, caps, mosfets, resistors etc. I don't have a choke or the Hall effect unit. I will have a go at building it. I have used arduino chips before, I had a friend help me with the programming and I made a solar hot water pump controller with one. It worked great. So I can load the programs onto the chip, I just need to get my head around what is on the boards. Thanks for the encouragement Pete |
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| Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 651 |
Good luck with the building, it gives great satisfaction when it works at the end. Do look for the info I sent you with the PCB's, I remember there was a small correction that had to be done. Else, if you got stuck just ask, I have a spare MPPT so I can turn the nano driven one off and look just what needs attention with my PCB. My memory is not as it once was .There is a lot of info about the choke required in that looong MPPT thread. |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1027 |
I'm not sure if anyone is interested but (maybe they should be) I will put up some thoughts. Many new inverters coming out lately now use high voltage solar input, I thought it might have been an idea to take the place of the GTI's when people get sick of getting little money for the power they (sell) provide to the grid. Many of these inverter have a generator input or grid input for pass through when batteries are low and a rectifier built in providing high voltage DC to the main inverter then through the converter stepped down to charge the batteries, usual stuff. Now forget the high frequency converter section for the moment, you have the main DC bus that is supplied by the solar charger and generator input is rectified and fed to the bus bar, all this needs to go to the high voltage inverter stage and then out to power whatever, in this case its just for EV charging. I know people don't like High voltage DC, neither do I but its the way all this new stuff is heading, instead of trying to sync inverter frequency as its not so easy, most of the work is done with DC, no problem getting multiple DC sources of the same voltage to the same place, no transformer needed, just need to have the inverter stage, much the same as the GRID TIE unit's we have used for parts. If this could be done and leave the offgrid inverters working as they are, just send power from 1 2 or 3 inverters to a box with a rectifier for each input that feeds the Inverter buss bar, will need some filtering and other things I have failed comprehend.  This should be great just to use all the solar production from multiple sources to charge an EV and thats all that the inverter has to do. I don't know how to regulate the amount of power each inverter can feed to the high voltage inverter buss bar, apart from some voltage drop. Obviously I don't know all the details but its the thought that counts. Warning I Wrote this before my cup of coffee.  Edit: Just made a cuppa, see if I can shorten the text that has scrooled across the page. Edited 2024-01-24 16:19 by Revlac Cheers Aaron Off The Grid |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
That sounds like an interesting idea. The output section of the inverter that is fed from the off grid inverters would have to be pretty big. I charged the car today from our 8 amp charger. My home made 8010 inverter handled it well and did not get too hot, even after charging for 4 hours straight. That managed to put in 40 kilometres of range into the car. I have a 15 amp charger coming that would double the range per hour to 20 kilometres per hour. So I need to be able to run a 3.6 kw inverter, continuously from my solar setup. I am still looking at the 2 x 3kw aliexpress boards to run one as the master and one as the slave. I have a stacked torroid core that I can rewind, it is 190mm od , 90mm id and 105 mm high. I will have to look at more stuff and do some calcs to see if I can fit the windings required onto this core. My calcs say I need to have a primary current of 276 amps, so a pretty serious winding on the primary side. Pete |
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