I-V translation procedure for higher accuracy and compliance with PERC cell technology requirements

摘要

The aim of this work was to re-evaluate the correction procedure 2 detailed in the IEC 60891, ed.2, because deviations (within 0.5% in P_(MAX) and 1.0% in V_(OC)) in the region between the maximum power point and open-circuit voltage have been observed between experimental and translated IV curves in PERC module types. The equations used in correction procedure 2 were revised to account for: 1. non-linear scaling of Voc against logarithmic irradiance, 2. irradiance-dependent temperature coefficient of voltage, 3. backward compatibility of IV translation and 4. temperature dependence of series resistance. The newmodified set of equations showed a reduction in the observed deviations between translated and measured I-V curves, when compared to the use of the original formulas. The improvements are noticeable in Voc. where accuracy gains up to 2.5% have been observed. Smaller in magnitude (up to 0.3%) but systematic accuracy gains were also observed in P_(MAX).