Real-time solar radiation intensity modeling for dynamic rating of overhead transmission lines

This paper investigates the effects of solar radiation intensity on the carrying capacity of transmission line conductors with different cross sections. The rated loading capacity of overhead transmission can decrease about 2% with the increase of solar radiation intensity of 100W/m². Thus, it is inappropriate to take the solar radiation density as a constant in load current capacity calculation for overhead transmission lines. In this paper, a new model of determining real-time solar radiation is proposed. This model is established based on the atmospheric attenuation law of solar radiation and incorporates a decay coefficient, which is obtained from a large dataset of historical measurements and meteorological conditions. The proposed model is validated by comparing the model predicated results with the real meteorological measurement results. The validation shows the proposed model is more accurate than the existing model as adopted in IEEE738-2006. The proposed may pave the way for implementing dynamic rating for the overhead transmission line's conductor.