question

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Problem with two Quattro in parallel. Sometimes instable.

Hello to all,

I have a problem with two Quattro. As soon as they run in parallel on the mains, the two inverters sporadically " oscillate ". They then make a loud humming noise and then switch off very briefly and then on again. Then it goes on again for some time without problems until it starts again.

With only one Quattro, the system works without any problems.

It also works without problems with both Quattro when the grid is switched off (off-grid).

The effect only occurs with parallel operation on the grid.

The AC and DC cabling is symmetrical (identical cables and cross-sections).

The AC and DC currents were measured and are almost identical/symmetrical (+/- 1-2 %).

The Quattro were parameterised with the MK3 via Quick-Configuration (network: Europe, as I live in Spain). Same type and firmware (updatet to newest).

It seems that the Quattro build each other up on the mains and then switch off briefly for safety. For a short time, very high currents (> 100A) flow on the DC side with only a low load.

I have already exchanged master and slave. Without any change. The problem persists.

No error message is displayed on the CCGX.

Can anyone give me tips on how to solve the problem?

Thank you very much!

Greetings from Spain, Thomas


211201 PV Stromlaufplan.pdf

MultiPlus Quattro Inverter Chargergrid parallel
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2 Answers
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tnt369 answered ·

Anyone have an idea how I can solve this?

Maybe it's the grid? What is the grid password so that I can adjust the grid parameters?

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tnt369 answered ·

Okay it is solved. Reason was the LOM function. With only one unit it was ok, but with both units there was a problem with the grid. Switched off the LOM detection and the system works stable.


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