Solmetric PVA-600, Руководство пользователя

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5 Interpreting Measured I-V Curves
5-2
I-V Curve Terminology
These abbreviations will be used in the following discussion:

Isc Short circuit current

Imp Max power current

Vmp Max power voltage

Voc Open circuit voltage

Vx Voltage at one half Voc

Ix Current at Vx

Vxx Voltage midway between Vmp and Voc

Ixx Current at Vxx

FF Fill Factor = Imp * Vmp / (Isc * Voc)
The fill factor (FF) of a PV module or string is a measure of the square-ness of the curve
as shown in Figure 45. PV modules of a given manufacturer and model will have similar
fill factors if performing normally.
Figure 45. The Fill Factor is defined as Imp x Vmp (the gray area) divided by Isc x
Voc (the cross-hatched area).
Series and shunt losses have a pronounced effect on the fill factor by changing the slopes
of the I-V curve near Voc and Isc, respectively, as shown in Figure 46.