With the help of the characteristic curve measurement, the actual performance of the module string can be determined on site and directly compared with the manufacturer's values specified in the data sheet. The modules do not have to be dismantled.
The manufacturer's specifications define the so-called "nominal characteristic curve", which serves as a reference for the measured characteristic curve.
After the measurement has been performed, the measured characteristic curve is compared with the nominal characteristic curve in order to be able to draw conclusions about possible errors. If the two characteristic curves differ from each other, for example by a significantly lower current or a lower voltage, this is usually an indication of an error.
The characteristic curve measurement is suitable for maintenance and performance control and as a preliminary measurement, in order to use more complex measurement methods, such as electroluminescence or infrared, in the next step.
PVS-Beer has more than 10 years of experience in characteristic curve measurement and uses the following equipment:
- PVE PVPM 1000 CX
- PVE PVPM 1000 C in combination with an additional device for automated module/strand measurement under favorable weather conditions (proprietary development)
- HT I-V 400
- Numerous reference sensors (partly additionally calibrated by Fraunhofer ISE)
Figure: Module string with significantly lower performance after lightning strike
Figure: Module string with significantly lower performance due to PID