
Characteristic curve measurement
If there is low yield, modules can be inspected on location with a curve tracer (in line with IEC/EN60891). Calibrated reference cells are a prerequisite for this. This method measures the power and current/voltage curves of the individual photovoltaic modules and of a module string. The values measured are converted to Watt Peak under standard test conditions (STC). (Sunlight strength 1000W/m², ambient temperature 25 °C)
Determination of the following values:
- Power in Wp (STC and OPC (operating conditions))
- FF (fill factor)
- RS – series resistance
- Determination of characteristic curve under STC
- Determination of characteristic curve under OPC
As a rule, analysis on location can be carried out faster and less expensively than a laboratory analysis (such as TÜV Rheinland, Fraunhofer …). But if there are major deviations, it is required to have the modules examined in a laboratory additionally after the measurement on location and the results have been verified.
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Characteristic curve measurement