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On Outdoor Testing Procedures of Large Samples of PV Modules
  • +3
  • Rodrigo Moretón,
  • Eduardo Lorenzo,
  • J. Solorzano,
  • Francisco Martínez,
  • M. del Pozo,
  • M. Muñoz
Rodrigo Moretón
Universidad Politecnica de Madrid Instituto de Energia Solar

Corresponding Author:r.moreton@qpv.es

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Eduardo Lorenzo
Universidad Politecnica de Madrid Instituto de Energia Solar
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J. Solorzano
Universidad Politecnica de Madrid Instituto de Energia Solar
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Francisco Martínez
Universidad Politecnica de Madrid Instituto de Energia Solar
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M. del Pozo
Universidad Politecnica de Madrid Instituto de Energia Solar
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M. Muñoz
Universidad Politecnica de Madrid Instituto de Energia Solar
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Abstract

STC power control of PV modules supply requires testing large samples of modules with low uncertainty. This paper analyses the feasibility of outdoor measurements with the modules kept at their operating positions. The classical procedure of recording I-V curves and translating them to STC in accordance with IEC 60891 using the cell temperature directly observed at a few points of the rear of the module entails uncertainties larger than 3% (k=2), which is too much for this procedure being accepted in quality controls with contractual consequences. A convenient procedure for overcoming this barrier consists in comparing the I-V curves of a tested and a reference module of the same type, both working under the same operating conditions. The latter is mostly secured if they are in adjacent positions. However, when the procedure is applied to large samples of PV modules kept in their operating position, the distance between both modules can reach tens of meters and significant inter-module temperature differences can arise. An artifice for counterbalancing these differences consists of estimating the temperature of the tested module and the “true” temperature of the reference module, as deduced from the V OC measurement, by the temperature difference observed at their respective back-sheets in a central position. This allows the measured power values to be corrected and provides clues to estimating the uncertainty of the results. This procedure has been applied in seven testing campaigns, carried out at commercial PV plants. Dedicated instrumentation, based on two radio linked I-V tracers, allowing the simultaneous measurement of the I-V curves and of the temperature at the centres of the reference and the tested modules, has been developed for that. The resulting uncertainties are slightly larger than those corresponding to high-quality solar simulators, but still low enough for dealing, in practice, with strict quality control requirements.
07 Mar 2023Review(s) Completed, Editorial Evaluation Pending
07 Mar 2023Submitted to Progress in Photovoltaics
07 Mar 2023Submission Checks Completed
07 Mar 2023Assigned to Editor
15 Mar 2023Reviewer(s) Assigned
31 May 2023Editorial Decision: Revise Minor
30 Jun 20231st Revision Received
30 Jun 2023Submission Checks Completed
30 Jun 2023Assigned to Editor
30 Jun 2023Review(s) Completed, Editorial Evaluation Pending
12 Jul 2023Editorial Decision: Accept