AC ohmic losses: reference power
See alsoand .
Basically, the AC wiring losses are calculated from the resistivity, i.e. the wire lenght, section and metal. During simulation, at each time step, the power loss is calculated as NWire * Rwire · I².
However in practice, as a first step of the design, people often use the relative ohmic loss. This relative loss should be referred to a specified Power.
Since the version 7.2, you have the opportunity of choosing as reference:
|-||either PNomPV(ac), the PV array nominal power at STC (PNomPV [kWp]), multiplied by the inverter's efficiency. This is the historical choice of PVsyst before the version 7.2.|
|-||or PNom(Inv), the nominal output power of the inverter(s), without temperature correction.|
This choice is done for each project, in the project's settings dialog.
In the main menu "Settings > Preferences > Physical models > AC Loss references", you may define the default initial value when creating a new project.