Classification of solar simulator characteristics
IEC 60904-9-2020 pdf download.Photovoltaic devices — Part 9: Classification of solar simulator characteristics
Dispositifs photovoltaIques — Partie 9: Classification des caracteristiques des simulateurs solaires.
b) Move the irradiance detector across the entire designated test area and take simultaneously recordings with the stationary cell. The recommended minimum step widths for both spatial directions are the detector dimensions. The maximum step width for both spatial directions results from the detector dimensions and to 80 % coverage requirement as defined in 5.3.2.2 . For an array detector the step width shall correspond to the spacing of detector cells.
c) Shift the reference point defined in step a) by half dimensions of the detector cell in both directions and repeat the uniformity measurement as described in step b). This step is only necessary when the associated positions have not already been covered in step b).
d) Determine spatial non-uniformity using formula (1) for both measured irradiance patterns.
e) The class of the simulator for non-uniformity is determined by the irradiance pattern with highest value of non-uniformity:
Class A+: Spatial non-uniformity of irradiance ≤1 %, as specified in Table 3. This classification can be only assigned if spectral match evaluation is performed
according to Table 2.
Class A: Spatial non-uniformity of irradiance >1 % and s2 %, as specified in Table 3.
Class B: Spatial non-uniformity of irradiance >2 % and s5 %, as specified in Table 3.
Class C: Spatial non-uniformity of irradiance >5 % and slO %, as specified in Table 3.
A table of the measured irradiance pattern should be supplied with the classification report to assist the user In testing and to clearly define different areas with different classifications and find the optimum test positions for different module/cell sizes.
1) If the irradiance patterns measured in steps b) and C) differ in spatial non-uniformity by more than 0,5 % (class A+) 11 % (class A) / 1,5 % (class B) I 2 % (class C) , a more detailed assessment of the uniformity should be undertaken, tailored to the intended use of the simulator. For example, a higher resolution measurement with a smaller detector (size-matched to the cell dimensions of the devices to be tested) would provide more useful data for the calculation of non-uniformity contribution to final measurement uncertainty, especially in cases where thin-film technologies of strip-like cell aspect ratio are to be measured. In such cases, the resulting additional non-uniformity information is for the benefit of the system operator and will not affect solar simulator classification.
For the verification of spatial non-uniformity (periodical maintenance work or onsite acceptance testing) a reduced number of measurement points is permitted. The details and best practice recommendations for different types of light source (single lamp. multi-lamp. lamps with integrated optics, etc.) are given in IEC TR 60904-14. The whole grid shall be measured If the difference of non-uniformity values, calculated from the restricted number of measurement points, and the previous or factory measurement is larger than: 0,5 % (class A+) /1 % (class A) /1,5 % (class B) I 2 % (class C) or If the non-uniformity value measured with the restricted number of measurement points falls outside the original classification.
5.3.3.3 PV cell solar simulator.IEC 60904-9-2020 pdf download.