Inverter Nominal Power @ 40°C

[Manuel Maier]

Good afternoon, 

I have a question regarding the nominal inverter power stated in the simulation report. 

The nominal power of an inverter, which is displayed in the report, is always based on the output at 40°C operating temperature. However, since the inverter (see picture below) has a maximum output of 352 kVA, the information stated within the report (320 kVA @ 40°C = nominal power) might be misleading and cause confusion when this report is shared with external companies, grid operators or similar - especially as the stated AC capacity is the Pnom,total and hence based on the nominal inverter power.

Is there a way to change the output power stated in the report to the maximum inverter power without manipulating the ond.file? I have also noticed the Pnom ratio is based on the nominal inverter power. Does this cause any issues with the energy yield calculation for projects in cooler regions with irradiation peaks > 1,000 W/m² such as in northern countries like Denmark or the Baltics?

Thank you in advance!

Edited May 30, 2023 by Manuel Maier

[dtarin]

Energy production is based off the OND file, so your inverter will output at Pmax according to Tamb and there should not be any concern for operations in cooler climates. You can output the 8760 and verify this. As for reporting, I am not aware of any way to display Pmax over Pnom in the report. You can add under report options some notes and alternate system sizes for clarification, and also edit the cover page to include details there. 

 

 

 

Edited May 31, 2023 by dtarin

[André Mermoud]

I admit that this definition may be confusing.  It has been established before the generalization of the maximum power possible increase according to the temperature.

But it is a choice. The convention is to specify the nominal values, not the derated values.

The maximum value, when used, is indeed mentioned on the report. 

And the PNom ratio in indeed an indicator, not a fundamental quantity. If we change the definition, other people will not be satisfied and there may be contradictions in other parts of the system interpretation. Moreover, if the inverter operates at high temperatures, what should be done ???