Shunt resistance criterion: Design and implementation for industrial silicon solar cell production

摘要

Silicon solar cell current-voltage (I-V) curve measurement is the final characterization procedure used in a photovoltaic (PV) industrial line. The illumination I-V curve measurements are of interest because they determine the solar cell power, relegating to dark characteristic in second place. Nevertheless, the growth of PV-building-integration can increase the possibility of the hot-spot phenomenon. The most effective approach to reduce this PV module failure is to directly identify and segregate malfunctioning cells in the production line. To achieve this objective, it is necessary to design a suitable silicon solar cell pass/fail protocol and to implement it in an industrial solar cell tester. This work focuses on the definition of a protocol for any industrial measurement tool for dark and reverse-biased conditions. The defined criterion includes three different orders: the first one segregates harmful Type I PV cells that exhibit a high hot-spot possibility, the second order separates solar devices that exhibit very high current leakage, and the third order separates PV cells with a double condition: Type II behavior that is very close to Type I with assembled power. This proposed dark-reverse measurement protocol has been appropriately defined for 125d150 and 150d195 PV cell sizes, and different batches for each size have been sorted using this scheme. The work also highlights the relevance of an in-line dark-reverse measurement criterion in a production-quality system. Finally, real size PV modules have been fabricated and they overcome the hot-spot endurance test.