Energy efficiency assessment of photovoltaic array on the stratospheric airship under partial shading conditions

Abstract

Accurate estimation of efficiency of airborne photovoltaic array on the airship has great significance for ensuring sufficient energy to stay in the stratosphere for months or a year. The solar irradiation and thermal model of the solar-powered airship have been studied. However, the interaction among the solar cells with different working conditions in the array has not been investigated. In this paper, the four main causes of nonuniform operating conditions including installation angle, angular losses, flight condition, and temperature are analyzed. The circuit simulation method is proposed, which determines the appropriate connection configuration of solar cells on the curved surface of airship at first. Then, the circuit analysis model of the connected solar array is built in Simulink. The I–V and P–V characteristic curves of the solar array are solved, and the maximum power point is tracked. The overestimation of output power and energy efficiency caused by using the empirical prediction model can be over 42.5%, and can be avoided by the proposed method in this paper. The work also provides an interesting reference for researchers to investigate reconfiguration and optimization of solar array on airship.