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Forum Index : Electronics : all home built solar system
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Yes one plug in central driver board that can be very quickly replaced if it dies. Although I am not sure paralleling is the best overall strategy. How about one inverter for the main house load, perhaps a second for heavy airconditioner loads, that might be turned off most of the time. Maybe a third for some large workshop power tools, that might also be turned off sometimes. If something smokes, a bit of unplugging and plugging in might get the show back on the road very quickly. Another thing to think about. If your only inverter dies after the grid has gone down, how do you fix it without power for soldering iron, oscilloscope etc ? I only have one inverter, but its completely modular, and I have a full set of spare boards and multiple spare IGBT modules. These can be very easily swapped out and I can replace whatever smoked by candle light if necessary, with nothing more than a screwdriver. Definitely no soldering required, no matter what. Edited 2022-01-13 16:33 by Warpspeed Cheers, Tony. |
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Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458 |
Hi Tony, Yep the multiple redundancy setup it best as far as I am concerned. No Grid here, I do have a generator but have not started it for over a year now. I really only use it for heavy welding jobs. Small welding the inverter runs my MIG welder fine. I have two separate systems, on large system (5kw panels, 660 amp hour batteries), for the house ( tiny house really) and one for a separate cabin.( 600 watts of panels 100 amp hour batteries. Four inverters in all. One latronics 2.3kw, three 8010 based 2 and 3 kw units. That is the downrated real watts not Chinese watts. I also have a gas soldering iron. and if all else fails well back to candles. Your modular inverter sounds great. Undoing lots of connections to get a board out to repair it can be painful. I try to leave lots of room in my inverter boxes but still they can end up pretty tight once all the heavy cables are in. Fortunately no air conditioner needed. We only ever get a couple of days a year near 30 degrees. The rest is low 20s in summer and around 0 to 10 in winter. Perfect climate for me. Cheers Pete |
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
It sounds lie you have it all pretty well covered. Cheers, Tony. |
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noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512 |
suggestion about paralleling inverters, Poida was working on a sync code in his poidaverter, it ended up being quite a lot of trouble syncing with a random sinewave, but if you could use a common clock source ( another nano or heck a 555 would probably be enough) and any / all inverters synced to said signal, then you could literally sync as many in parallel as the clock source / noise would handle... I think it works !! |
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Murphy's friend Guru Joined: 04/10/2019 Location: AustraliaPosts: 648 |
I played about with that syncing business of inverters. Yes, Poida's code works well to sync two sine wave inverters with no load on them. The trouble is when it comes to power sharing. As it was the inverters (or an inverter and a inverter type genny) would not share power evenly unless there was some kind of current feedback in play. I gave up then, it got too complicated for my limited knowledge. I suppose the idea of using a single nano driving different inverters should work but involves creating a reliable driving signal connection between them. Having more than one inverter works well for me if I run them independently. The house wiring for the lights and for GPO/power is separate, one inverter for each. A spare inverter could be put in service to power my shed & workshop if I wanted that. |
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406 |
Its much easier to sync to the grid, in fact grid tie inverters work exactly that way. A small generator is going to be a real problem, because unless its one of the newer "inverter generator" type, the engine rpm varies with load. As soon as you apply a load, the thing slows down. The rpm/frequency and voltage will be up and down and all over the place, and an inverter has zero chance of keeping up with it. If you need a generator to boost low solar in winter, much better to use it to charge the battery for a few hours as needed. Either that, or plug some or all loads straight into the generator direct. Same with mixing wind, hydro, solar, or whatever. Much easier to do all your power combining at dc using a few diodes. Cheers, Tony. |
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Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
Yes diode mixing DC is Soo easy and convenient, it's worth re-emphasizing. Especially with solar as the whole system just balances itself automatically and you can add more sources easily as required. |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
latest picoverter and powerboard Gerbers. I fixed the errors in the powerboard. Some TIP4x labeling was incorrect and the 10K pullup for the zener was just plain wrong. the picoverter has now got LCD (20x4) display and uses the 9600 baud "serial LCD" I use a lot The display shows inverter run status (on or off) heatsink and toroid temps and input volts Gerber_PCB_picoverter 6 w lcd.zip Gerber_PCB_madboard 5.zip wronger than a phone book full of wrong phone numbers |
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Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423 |
Which serial LCD do you use and where do you buy it? |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
I make it it uses a standard 20x4 LCD, maybe with I2C or without and a nano. a small bit of code loaded into the nano make it take serial data and put it onto the LCD. I do this since I've had a lot of problems with driving I2C LCDs directly, there is far too much EMI and the very lightly buffered I2C pins of the nano get upset easily, causing the chip to lockup The serial LCD thing presents 3 wires to the outside world. ground, 5V and data_in. Data_in is well buffered due to the arduino code using it as software serial. It seems far more reliable in the very noisy environment of inverters and mppt controllers. I just wire up the nano to the LCD, in the case of that pictured below it's non I2C, so I drive the 4 data pins, 2 control lines, 5V and ground direct from the nano. Then I have Gnd,5V and D4 on the nano coming out to be connected to the inverter or mppt. My inverter and mppt code uses a simple protocol. I send "$" to set the cursor at the beginning (0,0) and any other character is printed at the cursor position, moving it to the next location. load one of these into the nano.. nano_serial_to_parallel_LCD_2.ino.zip nano_serial_to_i2c_LCD.ino.zip Edited 2022-11-14 20:44 by poida wronger than a phone book full of wrong phone numbers |
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andymc70 Regular Member Joined: 30/06/2019 Location: AustraliaPosts: 43 |
Hello All I have been trying to find a supplier for the 60v to 15V DC-DC converter we use on the PICOVERTER and nanoverter brain boards. I only have 1 left and would like some spares. I can find plenty of 60V to 12V DC-DC converters with 3 amps, looking at Peter's schematic I can not see why we need the 15V version anymore. Happy if someone can show me why. I also have some LM2576hvt-15 regulators and was going to see if I can make my own. Thanks Andy |
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noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512 |
AU $8.17 5%OFF | 10PCS/LOT XL7015 DC-DC Dc converter Step-down module 5V-80V Wide voltage input 7005A LM2596 https://a.aliexpress.com/_mqpeuMw non isolated low power, these are good... AU $21.82 | 10PCS B0505S-2W B0505S-2WR2 B0512S-2W B0524S-2W B1205S-2W B1212S-2W B1215S-2W B2405S-2W B2415S-2W B2424S-2W SIP-4 NEW in stock https://a.aliexpress.com/_mOxp0xo isolated mosfet driver supply... AU $4.53 54%OFF | Converters Electric Buck voltage Converter DC36V/48V/60V/72V To 12V DC Module Car Power Supply Voltage For Electric Vehicle https://a.aliexpress.com/_mtrAuSI higher power non isolated... good for driving fans etc... hope this helps.. I think it works !! |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
Hi Andy The picoverter needs 15V for the IR2184 FET drivers. This permits driving a power board's FETs directly from the IR2184 If using a totem pole driver type power board then the 15V is not needed, it can be only 12V and this output will be sent to the transistors of the totem pole drive. I have not tested the picoverter with 12V supply for the IR2184 but I expect it will work with totem pole type power boards. Whichever supply you choose, keep in mind how much current will be needed when you include any fans that are to be driven from the supply. When only running the picoverter or nanoverter, only about 50mA is needed at 15V. Adding a fan could mean needing 0.7 Amps more, and larger fans will likely need some care in the 15V supply choice, even going to separate supplies for the fans. wronger than a phone book full of wrong phone numbers |
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tinyt Guru Joined: 12/11/2017 Location: United StatesPosts: 438 |
Another fan option is to use 240VAC fans powered by the inverter AC output. Or, if you are winding the output toroid, add an 11VAC or so winding connected to a bridge rectifier and capacitor. Size the magnet wire for the total fan current requirement. |
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andymc70 Regular Member Joined: 30/06/2019 Location: AustraliaPosts: 43 |
Hello Peter Thank you for pointing out why we need the 15V, I can now see that on the Schematic now. I need to pay more attention, it's always the smaller details that get me. I have found an adjustable version that could work, I am making sure the ones I have been looking for are around the 3 amps to run everything on the inverter. I do have some LM2576HV and I have been looking at the datasheet, lm2576hv.pdf I am looking to create the circuit on page 22, as I have the LM2576HV- adj, and find R1 and R2 (1k and 12K) that will give a 15V output. Please let me know if I am wasting my time. Thanks Andy |
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wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156 |
I have used the LM2576 adjustable modules on a number of projects and they work well for me with up to 56V in, the max I have ever used them with, the circuit you found should work just fine. The resistors you quoted give ~ 16V. Some possible ratios easily obtained are 39K & 3K480, 27K & 2K420, 18K & 1K6 (the second resistor in each case is made up of 2 in series using easily available values) they give 15.014, 14.95 & 15.06 respectively, assuming 1.23V internal ref voltage. If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike |
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naseerak Newbie Joined: 26/01/2024 Location: PakistanPosts: 5 |
Hi I dont see short circuit prtection in picovrter as opposed to nanoverter. |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
hi Naseerak in the builds of inverters I do (two for my home) I see no need for short circuit protection since I have contact breakers on the output AND DC contact breakers on the DC input. The HY4008 and others of that family have prodigious capacity for current conduction without failure if it's PWM. If it's DC then they are weak as you could ever imagine. This is by design. So, no need for short (defined as 0.01 second) very high currents since the FETs will shrug it off and ask for more. Long period shorts will be taken care of by functioning DC breakers and or AC output breakers. But here in Australia we tend to load our home built inverters with sensible loads and take care NOT TO SHORT THE OUTPUTS. The highest loads I've seen in my home is when the dishwasher is pulling 10 Amps and then we put a 10 amp kettle on too. This means about 20 Amps of 240W or about 5kW This is not a short. But then a fridge decides it's time to switch on... Things still do not blow up. Why? make sure the choke can handle these large currents and still be a choke and not a short piece of copper wire. put a 65 or 100 Amp breaker on the DC supply put a 150 Amp fuse before that. this is all assuming it's a 50V battery. with these sorts of loads you would be insane to choose 12V battery. really, really insane. wronger than a phone book full of wrong phone numbers |
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naseerak Newbie Joined: 26/01/2024 Location: PakistanPosts: 5 |
Hi is nanoverter produce uni polar signal? |
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poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418 |
yes wronger than a phone book full of wrong phone numbers |
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