Posted July 30, 20195 yr Hello everyone, Great forum I stumbled upon while researching a 3-phase 10kW hybrid inverter. I have some questions about our inverter and hope you guys can help me out. Type inverter: We have this inverter connected to 3 strings of 4 batteries in parallel (48V, 150Ah) and 330W * 8 solar panels. We currently have grid connected as well, but the system is designed to possibly go off-grid and maybe have a generator as AC input. We do not want to feed back in to the grid. If I understand correct these inverter are rebranded by companies. We setup the inverters with solarpower. We want to read out the battery capacity and if the capacity is too low, shutdown the AC output, load, or the system. We did a test by leaving the inverter on for a weekend (3 days) with the AC output on, but no load and only PV power and full batteries (no grid). The system was inside and so almost no sunlight (0,2A). We set the battery cut-off voltage at 42 Volts, but when we checked after the weekend on a monday, the batteries were discharged to around 22 Volts and the inverter was turning off and on because of the little PV power. The inverter was showing no battery voltage and giving warning code 15 meaning battery is unconnected or too low. Should the inverter not shutdown the AC output when capacity is too low or is there another settings that needs to be set? Unfortunaly the inverter did not record this data when we checked solarpower... I want to write a driver that can communicate with the inverter through modbus or serial direclty, but I am having some issues. We bought a modbus card for the intelligent slot and the company we bought it from provided us with the P17 modbus protocol. But when we do a modbus poll (function 3, read holding registers) on the given adresses they are all zero up until 8074 and more around 26000, but we don't know what the numbers represent. we set the modbus card to 19200bps and slave ID 1. Our preferred method would be serial communication (RS232), but I can't seem to connect to the inverter. I tried with a USB to RS232 converter and directly with a USB cable. I know the settings: baudrate: 2400 bps data length: 8 bits stop bit: 1 bit parity: none I also have the RS232 protocol document (https://s3-eu-west-1.amazonaws.com/osor62gd45llv5fcg47yijafsz6dcrjn/Infini_RS232_Protocol.pdf), but this kind of communication is new for me and I don't quite understand it. I tried throwing some command at it like "QPI", but without a proper connection I don't get any responses. Hopefully someone can steer me in the right direction, because I lost sight after all this research...
July 30, 20195 yr Hi @MrParadigm 5 hours ago, MrParadigm said: We want to read out the battery capacity and if the capacity is too low, shutdown the AC output, load, or the system. This inverter (like almost all the inverters on the market) is not able to determine the exact SoC as it does not feature integrated Coulomb-Meter aka Shunt. The InfiniSolar is guessing the SoC based on the battery voltage. Such technique works okay with FLA batteries, but not with the LFP as these have almost the same voltage regardless of their actual SoC. If you're okay with that, go on. If not, I would advise to combine the inverter with some kind of smart batteries with integrated BMS and readout the SoC from this BMS. As an alternative, Victron BMV712 is a good choice too. 5 hours ago, MrParadigm said: We did a test by leaving the inverter on for a weekend (3 days) with the AC output on, but no load and only PV power and full batteries (no grid). The system was inside and so almost no sunlight (0,2A). We set the battery cut-off voltage at 42 Volts, but when we checked after the weekend on a monday, the batteries were discharged to around 22 Volts and the inverter was turning off and on because of the little PV power. The inverter was showing no battery voltage and giving warning code 15 meaning battery is unconnected or too low. Should the inverter not shutdown the AC output when capacity is too low or is there another settings that needs to be set? Unfortunaly the inverter did not record this data when we checked solarpower... There's a ton of ways how to set the InfiniSolar. Normally, the inverter should turn-off when the batteries fall under cut-off voltage. If there's AC grid present, the inverter will go into bypass mode. If there's no AC grid present, the Inverter will shutdown. BTW, that the reason why you have option to set two cut-off voltages. BUT: if there's even a bit of voltage present on the MPPT input (like 200V or so) , the integrated solar charger (SCC) will stay online and will slowly drain the batteries...as the panels have Voltage, but not enough Amps to supply the SCC. Maybe that you've drained the batteries during the first day, inverter went off, but SCC was continuing to drain the batteries over next two days. Anyway, if you're looking for an off-grid application, I do recommend to set the operating mode to Off-Grid III. Also, enable these two settings: Allow battery to discharge when PV is available Allow battery to discharge when PV is unavailable 5 hours ago, MrParadigm said: I want to write a driver that can communicate with the inverter through modbus or serial direclty, but I am having some issues. We bought a modbus card for the intelligent slot and the company we bought it from provided us with the P17 modbus protocol. But when we do a modbus poll (function 3, read holding registers) on the given adresses they are all zero up until 8074 and more around 26000, but we don't know what the numbers represent. The InfiniSolar has an RS485 communication, but it's being used primaryly for interacting with the smart-meter (ET112) or with BMS (Pylontech). There IS a way how to monitor and manage the InfiniSolar over the RS485, but not directly. For this, you need an extenal box called SNMP Box: https://www.mppsolar.com/v3/portfolio/snmp-module/ The box is connected to the infini via RS485, to the computer via TCP. It provides WebGUI, together with a crappy implementation of basic SNMP. Second option is a card that provides TCP and WebGUI directly. It's very similar to the card that you've purchased, but it has a LAN port. BUT I've never heard of a person that was able to hijack the InfiniSolar's RS485 in order to emulate SNMP Box with Rapspberry or Arduino.So, I would recommend you to ditch the RS485 idea and use RS232 or USB instead. 5 hours ago, MrParadigm said: Our preferred method would be serial communication (RS232), but I can't seem to connect to the inverter. I tried with a USB to RS232 converter and directly with a USB cable. I know the settings: baudrate: 2400 bps data length: 8 bits stop bit: 1 bit parity: none I also have the RS232 protocol document (https://s3-eu-west-1.amazonaws.com/osor62gd45llv5fcg47yijafsz6dcrjn/Infini_RS232_Protocol.pdf), but this kind of communication is new for me and I don't quite understand it. I tried throwing some command at it like "QPI", but without a proper connection I don't get any responses. You have the wrong protocol. The document in your link is for "InfiniSolar V", which is a machine with a completely different CPU. It's basically an Axpert. Therefore, it's using Axpert RS232 comm protocol.For your inverter, you will need a different procotol, that's being used for "REAL" InfiniSolar machines. Like InfiniSolar Plus 3K, 5K and 10K. Try to issue these commands over the RS232: ^P003ID<cr> ^P004VFW<cr> ^P003MD<cr> ^P003GS<cr> ^P003PS<cr> Every command ends with a Carriage Return character aka 0x0D. It's safe to use PUTTY.EXE for these tests. Don't forget to turn-on "local echo" in the Putty. Complete protocol PDF attached. Good luck buddy! Youda Infini-Solar 5KW protocol 20160309.pdf Edited July 30, 20195 yr by Youda
July 31, 20195 yr Author Thanks for the quick response Youda, 19 hours ago, Youda said: This inverter (like almost all the inverters on the market) is not able to determine the exact SoC as it does not feature integrated Coulomb-Meter aka Shunt. The InfiniSolar is guessing the SoC based on the battery voltage. Such technique works okay with FLA batteries, but not with the LFP as these have almost the same voltage regardless of their actual SoC. If you're okay with that, go on. If not, I would advise to combine the inverter with some kind of smart batteries with integrated BMS and readout the SoC from this BMS. As an alternative, Victron BMV712 is a good choice too. As we could not figure out how to communicate directly over modbus (which is not really a option as you've explained in your post), we actually installed a shunt meter (https://tbs-electronics.com/product/expert-modular-battery-monitor-12v-24v-48v/) to measure our batteries (The batteries we use are lead carbon batteries). But thanks for heads up 19 hours ago, Youda said: There's a ton of ways how to set the InfiniSolar. Normally, the inverter should turn-off when the batteries fall under cut-off voltage. If there's AC grid present, the inverter will go into bypass mode. If there's no AC grid present, the Inverter will shutdown. BTW, that the reason why you have option to set two cut-off voltages. BUT: if there's even a bit of voltage present on the MPPT input (like 200V or so) , the integrated solar charger (SCC) will stay online and will slowly drain the batteries...as the panels have Voltage, but not enough Amps to supply the SCC. Maybe that you've drained the batteries during the first day, inverter went off, but SCC was continuing to drain the batteries over next two days. ok, thanks for confirming my suspicion. The thing is, why is it allowed for the SCC to keep draining the batteries when the inverter is below the cut-off voltage (when there is no AC grid present)? is disabling the MPPT switch the only option to prevent this? 19 hours ago, Youda said: Anyway, if you're looking for an off-grid application, I do recommend to set the operating mode to Off-Grid III. Also, enable these two settings: Allow battery to discharge when PV is available Allow battery to discharge when PV is unavailable Would the inverter not behave like a Off-Grid setup when the AC grid input is not present in the Grid-Tie with backup mode? What does those two settings exactly do? We noticed if we enabled them, it would discharge the batteries when Grid and PV was available. We thought it might be better to leave the batteries topped-off and only discharge if there is not enough PV (or grid). 19 hours ago, Youda said: So, I would recommend you to ditch the RS485 idea and use RS232 or USB instead. Noted. I wanted to use RS232 anyway, but had trouble getting the protocol as our supplier didn't want to share it with us. So thank you for the document 19 hours ago, Youda said: Try to issue these commands over the RS232: ^P003ID<cr> ^P004VFW<cr> ^P003MD<cr> ^P003GS<cr> ^P003PS<cr> answers: ^00251496161809100219000000{▒ ^D017VERFW:00001.01VW ^D037000,010000,99,3,3,2300,2300,04,120U▒ ^D1100000,0000,0000,0000,0540,100,+00000,2386,2380,2386,5001,0000,0000,0000,2386,2382,2380,4998,,,,033,037,000,0A▒ 6^D10100000,00000,,+00022,+00022,+00021,+00065,0000,0000,0000,00000,0286,0261,0262,00809,008,1,0,0,1,1,1▒▒ Thanks so much, I can work with this. I am going to play with it more tomorrow as I don't have time left today. what do the responses mean exactly? batterX_Battery-carbon-EN.pdf Edited July 31, 20195 yr by MrParadigm
July 31, 20195 yr Shunt = good job! When the battery reaches cut-off voltage, the inverter will turn-off AC out and if there's no PV power comming from the MPPT, then the SCC will die in a couple of minutes too. LCD will be completely dark. So, overnight, the SCC is not draining the batteries normally. The drainage problem is visible only the mornings/evenings when SCC starts because the voltage comming from the MPPT will wake it up. But since the PV power is not strong enough to feed the SCC's self-consumption, it will slowly drain the batteries or cycle on/off and search for the rising Sun. If you will use the inverter with a decent array of panels situated outside, you should not experience any problems with battery being drained over the weekeds...assuming that the Sun will rise at least on Saturaday or Sunday, of course To explain the differences between the operating modes of InfiniSolar is beyond the time that I'm willing to spend here....So, you have to trust me that for the the real off-grid operation the best mode is Off-Grid III + to enable couple of meaningfull checkboxes. If there will be enough sunlight, the loads will be powered from the PV and batteries will stay charged. Overnight, the batteries will supply the loads. Commands: ^P003ID............................inverter serial number ^P004VFW......................primary firware ^P003MD......................device model and AC rating ^P003GS........................operating values of PV and Battery ^P003PS.......................solar and AC power The last two are the most important query commands for any homebrew automation. The PDF is quite self-explanatory and decoding the values is easy since they are transfered as plaintext decadic numbers.
July 31, 20195 yr Author Youda thank you for the help, I can continue working on this project now. P.s. I've read into your solar setup at home. Very nice build and a interesting read. :)
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