Add MPPT Efficiency to List of .OND File Contractual Specifications Without Real Physical Meaning

[kjs55]

Hi:

PVsyst v6. Please add MPPT Efficiency to the list of "Contractual specifications, without real physical meaning" in the .OND file.

This value is commonly reported on datasheets, etc. It relates to unavoidable losses from oscillations about the knee of the power vs. voltage curve (e.g., due to granularity limitations from both component/hardware choices and software algorithms--these losses are unavoidable even with an ideal curve). It would be good to keep track of the nameplate value in an inverter's .OND file.

Thanks.

[Lazare Fesnien]

Hi,

The efficiency is the ratio of the output power with respect to the input power. It depends mainly on the power and can also be a function of the input voltage.

In PVsyst there are 4 ways of defining the efficiency of inverters :

- from a single efficiency curve eff = f(Input power), specified by up to 8 points

- from a single efficiency curve eff = f(Input power), automatically built from the Maximum, EURO or CEC efficiencies and the Power Threshold (Pthresh)

- from a set of 3 efficiency curves eff = f(Power, input voltage), all of them specified by up to 8 points

- from a set of 3 efficiency curves eff = f(Power, input voltage), all of them automatically built from the Maximum, EURO or CEC efficiencies and Pthresh.