Mismatch loss analysis of solar array output power on stratospheric airship during flight

Abstract

Stratospheric airships are long-endurance aerostats and have broad applications. All of the energy required for their operation is obtained from solar radiation, which makes accurate calculation of the energy output from the solar array crucial to the design and flight planning of the airships. However, the status of each photovoltaic module in the solar array may differ due to the airship curvature, resulting in mismatch losses and lowered output power, which has not been widely studied. In this paper, an irradiation model and a thermal model are established based on the actual arrangement of the modules. The output power model is established considering the non-uniform radiation in the array. The mismatch losses of the array are analyzed under different flight conditions. The output power of the solar array is decreased by up to 31.6% compared to the ideal state. Moreover, the proportion of mismatch losses increases with latitude, but the maximum mismatch loss power occurs at mid-latitudes. Then, an array reconfiguration method is proposed based on the irradiance dispersion index and position dispersion index. The reconfigured array increases output power by 11.5% and can maintain energy balance in continuous flight. The results can be used to correct the overestimation of the output power during the airship design or to guide the configuration of the solar array.