power factor（cos phi）-The set value differs from the calculated result.

[jack chen]

I have a question regarding the power factor. I set the power factor（cos phi） to 0.9 in PVsyst Version 7.4, but the energy flow diagram in the calculation result report shows it as 0.894. I would like to know the reason for this discrepancy.

[jack chen]

"I want to know whether such calculation results are normal and what the reasons for such differences are？

[Luca Antognini]

You can find the detailed explanation to your question in our documentation on the power factor : 

https://www.pvsyst.com/help/project-design/grid-connected-system-definition/power-factor/index.html

Check in particular: https://www.pvsyst.com/help/project-design/grid-connected-system-definition/power-factor/Simulation results.html

In short: the power factor that you set in the menu "Energy management", here cos(phi)=0.9, is the power factor at the inverter level. The reactive power will be computed from the available power at the output of the inverter as EReGrid=EOutInv×tan(ϕ). We assume that there is no loss of reactive energy from the inverter to the injection point. However, we assume active energy loss in the AC circuit. Therefore, the power factor at the injection point will be decreased compared to the setting at the inverter output.