An alternative method to IEC 60891 standard for IV curve correction based on a single measurement

In the expanding field of photovoltaic solar energy, it is often necessary to apply a correction method to I-V curves measured outdoors and translate them to standard test conditions (STC). The international standard IEC 60891 serves as a primary reference for correction methods, but its application is not straightforward in the case of outdoor photovoltaic strings. Even for photovoltaic modules, this standard requires measurements of several IV curves under controlled conditions to determine the parameters, which makes the procedure experimentally complex. An essential correction method should avoid additional measurements and provide an uncertainty comparable to IEC 60891, especially for outdoor measurements. In this paper, a novel method is presented in which the correction of the I-V curve is performed without additional measurements. The method is based on procedure 1 of IEC 60891, in which the parameters for the correction of the I-V curve are determined by iterative processes via the linear correction of the maximum power with temperature and irradiance. The new method was tested for both indoor and outdoor measurements. The method showed an uncertainty of less than f 2 % in the maximum power of the corrected curves. This method can be implemented in spreadsheets and offers an alternative with similar accuracy to method 1 of IEC 60891, while maintaining the simplicity of the correction by using only the measured curve and the values of the temperature coefficients of the photovoltaic modules.