Thanks Andre for the quick response. Unfortunately all the string inverters that we work with have this type behavior. I understood PVSysyt can model two zones: where you have full power (540-800 V constant), and where the inverter cannot deliver full nominal voltage when the input voltage is too low (this is the zone between 240-540). For this particular case, we were thinking about model the parameters like stated below. Minimum MPP Voltage 240 V Min. Voltage for PNom 540 V Nominal MPP Voltage N/A Maximum MPP Voltage 800 V Absolute max. PV Voltage 1000 V We interpreted that doing this, we are estimating the lower voltage behavior and the maximum power mpp window (540-800 V) and we are not taking into consideration the higher voltage behavior (from 800-950V). If we assume that 'Maximun MPP Voltage is 950V, we will be overestimating the production for higher voltages (800-950V). Do you think our thought process is correct? Do you recommend to have a different approach in order to do the most accurate modelling? Thanks a lot for your help, Best regards Mercedes