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Ovidiu Stan avatar image
Ovidiu Stan asked

AC IN Current limiting bug in parallel installations


   
                  Hello people. A few months ago i discovered a a bug in limiting the input current to AC IN for Multis/Quattros, but ONLY IN PARALLEL SYSTEMS. If I only have 1 Multi/Quattro per phase, the limitation works perfectly, but when I have at least 2 inverters per phase (as is the case with one of my systems - 6 Quattros 15 000, three phase,  parallel, 2 Quattros per phase)  it no longer works as it should. More precise, if I set In Ve.Bus System Configurator, let's say, a limit of 35 amps for each inverter, that is 70 A per phase and after that I upload the configuration on the inverters, it works ok. If, however, I later need to increase or decrease the respective limit, let's say to 75 A per phase, the VeBus system, normally, as specified in the manual, should divide 75 A by 2 = 37.5A per inverter . But it only does this with the Master inverter, the slave still remains with the initial setting in VeConfigure, in this case, of 35 A. Because I make programming in Node-Red for these systems through which , in order to force the system to take current from the batteries, I set the limitations to AC IN dynamically, depending on the SoC: for example, up to 20%, let me accept a limit of, say, 70A per phase, and below 20%, let me increase limit to 100 A per phase, so that the batteries do not run out at night, this bug prevents me from doing this dynamic AC input limiting. I repeat, this works perfectly for simple single-phase and three-phase systems, but it does not work at all in parallel. I kept hoping that someone from Victron would discover this bug and solve it, but it didn't happen untill now, so maybe they will see this here or maybe someone here has found an workaround. I am also attaching a video/screenshot for better understanding.
Node-REDmultiplus in parallelbug report
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2 Answers
derrick thomas avatar image
derrick thomas answered ·

This is normal in parallel setups. The master is always in control of the slave so the current limit is being controlled by the master and not the slave. The current limit setting in the slave is meaningless.

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Ovidiu Stan avatar image
Ovidiu Stan answered ·

screenshot-20230817-201407-chrome.jpgNo, it's not normal. When you set the limit for 60 amps, for example, the system divides this equally to the number of inverters. If you have 2 inverters, each gets a limit of 30 amps, if you have 3 inverters, each gets a limit of 20 amps, and so on. My issue is that this works perfectly when it's configured via Ve Configure, but it doesn't work when it's configured remotely through the control panel in VRM or through Node-Red.


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nickdb avatar image nickdb ♦♦ commented ·
You are misreading this. What you set will be multiplied by the number of parallel inverters. You need to divide it by the number of systems for it to work.

If you set 60A on the master and you have 3 inverters, that equates to 180A.

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