Max Voc of Fronius ECO 27

[Vishnu]

Hey Valentin Team,

I tried simulating one of our PV systems with Fronius ECO 27 inverter, which as per its Datenblatt, has max input voltage of 1.000V

The modules I used are SOLON R-WF 120p.2/370 with max Voc of 40,81V

There is a warning that max Voc of inverter is crossed when I used 24 modules (24*40,81 = 980V) on one string.

What am I missing here??

Thank you!!

[developer_fw]

Hi Vishnu,

sorry for the belated answer. Could you be so kind and send the project file via private message here in the forum?

Thanks in advance and best regards,
Frederik

[developer_fw]

Hello Vishnu,

thank you for the project file. You must not forget the temperature set for the open circuit voltage check, which is not the STC condition of 25°C. Due to the voltage coefficient of the modules the maximum voltage is reached at -10°C:

At the moment there is no function to set this temperature automatically based on the climate data. This is on our feature list. You can set this value in the configuration limits. But considering your location, it does not solve the problem of exceeding the voltage limit. I thought the plant might be planned for a warmer location where temperatures don't drop so much.

Even under STC conditions (25°), the boundaries are narrowly chosen. A reasonable buffer to avoid overvoltage is very important!

I hope this helps. Best regards!
Frederik