Once the Incident Global Effective irradiation and the MPP running conditions are determined, the grid system has to take the inverter behaviour into account, that is:
| - | If EArrMPP doesn't reach the inverter input threshold, the array is considered as open circuit (I=0 and U=Voc). |
| - | If the inverter output power exceeds it's nominal power, it behaves according to the definitions of the inverter characteristics, that is: |
| Limitation: the inverter searches, on the array I/V curve, the running point corresponding to it's output nominal power PNom(eff), by decreasing the operating current. |
| Cut: the inverter input is cut off, the array is considered as open circuit, the power is null. |
| Cut until morning: once the cut-off has occured, the inverter doesn't run until the next morning (very old inverters). |
The maximum nominal power used here is indeed the effective PNom, which may depend on the temperature of the inverter and the Power factor.
| - | When the MPP voltage reaches the minimum or maximum voltage of the inverter's MPP window, the array voltage stays at this value on the I/V curve. |
| - | Otherwise, in normal operation, the inverter drives the array at the MPP, it's input energy is EArrMPP, and output energy is calculated according to it's efficiency curve. |
For each case, the energy loss with respect to the MPP ideal running is independently accumulated, as well as the array operating voltage and current.
Finally if user's load has been defined (corresponding to the own consumption of the user), self-consumed and re-injected energies are accounted.
The main output variables calculated here are: InvLoss, EArray, EoutInv, Euser.
