EN IEC 60904-1:2020 pdf free.Photovoltaic devices – Part 1: Measurement of photovoltaic current-voltage characteristics (IEC 60904-1:2020).
When the measurements are intended to be reported at standard test conditions (see 4.5)the in-plane average irradiance during measurement shall be between 800 w.m-2 and 1200 w:m-2 to minimise errors arising from large corrections.
Temperature sensors should be located so as to detect as closely as possible the temperature of the respective device cell junction. If a temperature gradient between thesensor and the cell junction is suspected, an appropriate contribution to the measurement uncertainty should be included.Consideration should also be given to any possible non-uniformity of temperature across either device,particularly for PV modules,where the temperature of individual cells can vary due to their electrical characteristics, particularlywhen the module is illuminated under short-circuit conditions. The Equivalent CellTemperature (ECT) method specified in lEC 60904-5 can be useful in dealing with either atemperature gradient or temperature non-uniformity.The cooling effect from airflow (forexample due to wind during outdoor measurement or due to air conditioning of the room forindoor measurements) on the temperature sensors should be considered in the uncertaintyof the temperature measurement.
The active surface of the device under test shall be coplanar within t2° with the activesurface of the reference device.
Voltages and currents shall be measured using independent leads from the terminals of thedevice under test and keeping them as short as possible. lf the device under test is a module,a subassembly or an encapsulated solar cell,the 4-wire connection should start at theterminals or connectors. If the device under test is a bare PV cell, the 4-wire connectionshould start at the cell bus bars.The connection method for bare cells (i.e. provided withoutconnectors) should be carefully evaluated. Differences can occur if soldered tabs are usedcompared with non-soldered methods such as bars having contact springs or conductiveplates having a large-area contact with the cell back contact. Non-soldered methods canresult in higher fill factors than are observed in the module.The contacting method shouldbe appropriate to the intended use of the cell or of the measurement.The contact methodused (bare cells) or the contact point (modules) for 4-wire connection shall be stated in the report. For bare solar cells without busbars or cells with low surface conductivity such as multi-busbar cells,4-wire connection should start at the contacting structure in order to avoid artificially increased fill factors in the measurement caused by voltage drop at the resistance between current and voltage probe on the cell.Possible deviations between the calibration of the measurement system (typically under static load conditions) and its useduring I-V curve measurements (dynamic load conditions) shall be considered.EN IEC 60904-1 pdf download.