Irradiance uniformity reshaping method for solar simulators based on computer-generated spatial filter films

Irradiance uniformity is critical to the accuracy of photovoltaic device test results. Therefore, to post-correct the irradiance uniformity inherent in artificial lighting systems, a spatial irradiance filter scheme for film patterns is proposed based on the physical phenomenon of a positively related relationship between inkjet concentration and the transparency of the flexible film. The scheme first establishes the characteristic equation between the irradiance absorption and pattern grayscale values and then generates the spatial filtering pattern by utilizing the light intensity distribution to be calibrated, matrix operations, and bilinear interpolation. To evaluate its performance, an STM32 microprocessor-based irradiance distribution measurement system was developed and used to test and verify single lamp, planar array, and curved surface array light sources. The results reveal that the corrected irradiance uniformity improves by 15.5%, 24.01 %, and 13.11%, all of which achieve the Class A irradiance uniformity of the IEC 60904-9 standard.