Model step
AC ohmic wiring
Resistive loss in the AC wiring at the inverter
Inputs used: AC circuit: loss fraction at STC, AC wiring model, AC power reference, Power factor
What it is
The AC cables between the inverter and the transformer turn part of the power into heat. The design gives the loss as a fraction of the inverter output at the power reference. The options set how the loss varies with the output.
Options
- k·P² on the inverter output: the loss grows with the square of the inverter output
- Flat fraction: a fixed fraction of the inverter output, the night consumption included
References
- PVsyst 8 help, AC losses
- NREL SAM Simulation Core (SSC) source code, release 2026.7.3, github.com/NatLabRockies/ssc: ssc/cmod_pvsamv1.cpp, the AC wiring, transformer and transmission losses in exec(); shared/lib_power_electronics.cpp, Transformer::transformerLoss()
API
ac_losses.ohmic_model = ohmic_i2r | flat, ac_losses.ac_wiring_loss_at_stc