Fixed (!) Ohmic Losses

[Lockyy]

Hello,

I am trying to calculate a project and want to compare different inverters and panels. But every time I change the system, the ohmic losess (percent) change. At this point I don't want to vcalculate cables or anything. Is it possible to keep the losses fixed to values like 1% or 1.5% and NOT xy mOhm? If not, is there a chance to make it possible in a future version of PVsyst?

Thanks in advance!

Lockyy

[Lockyy]

Any ideas anybody?

[dtarin]

If you are talking about DC ohmic losses, just enter the percentage you want to use. Click the cursor into the wire resistance field above after updating the percentage, and then click back below into the percentage field. The mOhm should update when you first click into it after updating the percentage.

[Lockyy]

If you are talking about DC ohmic losses, just enter the percentage you want to use. Click the cursor into the wire resistance field above after updating the percentage, and then click back below into the percentage field. The mOhm should update when you first click into it after updating the percentage.

 

Yes I know. But every time I change the system (less modules, more modules), the mOhm stays fixed and the percentage changes to 1.13% or 0.88%,...I want the percentages to stay fixed 1%.

[linkeshd]

Hi,

I believe that the behavior you are experiencing is because PVsyst calculates the percentage based on the actual wire, not the other way around. If you add modules, you are also adding wire, which means higher ohmic losses.

AFAIK no way to get around that. However, maybe using the "Target Loss Fraction" in the "Detailed Calculation" of Ohmic losses would tell PVsyst to keep it there?

Good luck!