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Chararcterizing the angular distribution of an LED-based solar simulator for PV modules

07.10.2019

Solar simulators for PV modules often consist of several lamps arranged side by side to provide the irradiance necessary for PV module testing under standard test conditions. Since these simulators are no point sources, the angular distribution of the radiance emitted by the simulators can lead to systematic deviations in measured PV device’s performances. To quantify the opening angle of a solar simulator, pictures of a digital single-lens reflex (DSLR) camera and irradiance measurements of a CCD-array spectroradiometer were combined to derive its approximate spectral radiance distribution. We applied our technique to an LED-based solar simulator, where the radiance of 18 different LED colors could be examined separately and thus an approximation of the spectral radiance emitted by the simulator can be made. An angle of incidence of 15.6° has been observed for this system at the center of a PV module, raising to about 21.5° towards the edge of the test plane.

Figure 1: Picture of the LED-based solar simulator with all 18 LEDs turned on. Left: Uncorrected RAW picture. Right: Vignetting- and distortion-corrected picture.

 

Author:

Riechelmann, Stefan
Physikalisch-Technische Bundesanstalt (PTB)