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.
