OND file: Inverter Power Consumption using "Auxiliary Consumptions"

[david.stone]

In OND files, we are trying to understand how to use the auxiliary consumption fields under the additional parameter tab, to properly characterize the inverter power consumption.

• Assuming that the “fans and auxiliary” value is power over and above that characterized in the power threshold value….?

• Are these losses subtracted from EOutInv, or maybe EArray?

• Is the “Fans and auxiliary” value subtracted during hours of operation (once the power threshold is exceeded)? Is “Night consumption” subtracted during the other hours?

• We don’t understand the “... from output power” field. What happens if this isn’t set to the power threshold value found under the main parameter tab? How does this field relate to the power threshold field?

[André Mermoud]

Some answers to your questions

• Assuming that the “fans and auxiliary” value is power over and above that characterized in the power threshold value….?

The loss is indeed accumulated at each time step, as soon as the instantaneous power delivered by the inverter exceeds the "Power threshold".

• Are these losses subtracted from EOutInv, or maybe EArray?

They are substracted from EOutInv, as shown on the array loss diagram.

• Is the “Fans and auxiliary” value subtracted during hours of operation (once the power threshold is exceeded)?

Yes,

Is “Night consumption” subtracted during the other hours?

It is substracted when the inverter's output is 0.

• We don’t understand the “... from output power” field. What happens if this isn’t set to the power threshold value found under the main parameter tab?

This field has nothing to do with the "Power thhreshold" of the main parameters, which is the minimum array power at which the inverter begins to produce.

[sidom]

According to the previous questions:

I have been making some changes in the "fans and auxiliary" value but the final results do not change. It seems that it doesn`t work properly. However, "night consumption" value works fine.

Could you please explain the meaning of the “... from output power” field?

Thanks

[André Mermoud]

The Auxiliary losses (formerly defined in the inverter's parameters) is now specified in the "Detailed losses" for the simulation.

The values of the inverter are just used as default values for this parameter choice.

The field "... from output power" means that the fans are switched on only when the inverter output power exceeds this value.

[sidom]

Regarding the Auxiliary losses of the Detailed Losses, when introducing some consumptions in "Continuous Auxiliary loss" input parameter, why the simulation report calls to these losses night consumptions instead of online consumptions or just consumptions? These are consumptions during operation and not night consumptions? Is this correct?

Thanks

[André Mermoud]

Sorry, this is indeed an error in the translation file.

For the Spanish and the Italian languages we have the inversion

- Ausiliari (ventilatori, altro…) <=> Consumi notturni

- Auxiliares (ventiladores, otros …) <=> Consumo nocturno

Thank you for pointing this out. Such an error is almost impossible to detect by our own means.

This will be corrected in the version 6.33.