Modeling Spectrum Dependent Characteristics of Triple Junction Solar Cells for Solar-Powered Aircraft

Abstract

To build a high-altitude solar-powered aircraft with persistent flight capabilities, an energetic analysis during development is essential. The German Aerospace Center (DLR) is currently developing its own demonstrator aircraft. To investigate the power income of the aircraft's triple junction solar cells, a simulation model is necessary. Most important different spectral irradiance influences shall be considered for calculating electrical characteristics. Besides analyses the solar cells shall be simulated for a hardware-in-the-loop (HIL) testbed too which leads to real-time requirements. Because simulation models of solar cells with the listed capabilities were not existing, a new approach had to be developed. The external quantum efficiency (EQE) and a pre-measured current-voltage (I-V) curve are the key tools to calculate the cells' new I-V curve to a given spectrum. First validation results attest accurate results at different spectra conditions and a consistent runtime of less than 20 μs on the target hardware.