In a recent study published in the journal Energies, researchers from China analyzed the effect of the unconventional configuration of the joint wings of solar-powered aircraft with an increased dihedral angle to improve energy acquisition by minimizing the power loss caused by the mismatch in the photovoltaic system.
Study: Energy Acquisition of Solar-Powered Joint-Wing Aircraft Considering Mismatch Power Loss. Image Credit: BokehStore/Shutterstock.com
They adopted a new method based on the simulation of an energy system to measure the mismatch power loss of the joint wings, which indicated a 4-15% deviation from the previously used estimation methods. Additionally, the new configuration showed an increase in sensitivity to the coupling between configuration and trajectory, and the mismatch power loss was found to be influenced by the curved upper surface, the severity of shading, and the circuit configuration.
Solar-Powered Joint-Wing Aircraft
Solar-powered aircraft are energy efficient and environmentally friendly solutions to present fossil fuel-based aircraft that perform long flights lasting for periodic days and nights up to several weeks. These aircraft have photovoltaic (PV) cell arrays installed on the upper side of their wings that convert solar energy into electricity during daytime, and the produced electricity is directly used by the propulsion system and other airborne equipment during both day and night.
Present solar-powered aircraft prototypes have the conventional configuration of straight wings with low wing load and high aspect ratio. However, they have disadvantages related to structure and flight range owing to low stiffness and strength. Moreover, in high-latitude areas, a small sun elevation means a large angle of incidence on PV cell arrays, thus low direct solar irradiance and reduced energy harvesting.
As a solution to the disadvantages of conventional wing designs, unconventional wing designs incorporate “v” -shape with increased dihedral angle (vertical angle of wings with horizontal axis), “Z or N”-shaped morphing wings at the back of each fixed primary wings, and active tracking of the sun to increase direct solar irradiance capturing.
Energy acquisition estimation of solar-powered aircraft. Image Credit: Ji, X et al., Energies
Furthermore, the traditional energy capturing measurement method assumes coplanar PV cells configuration, which underestimates the power loss caused by two types of mismatches. The first mismatch is due to the nonuniformity of irradiation on solar cells in the same solar module that leads to a mismatch in the net series connection and the second one is due to the nonuniformity of irradiation on solar modules in the same solar array due to partial shading or different orientations.
About the Study
In this study, researchers integrated several 24-hour flight simulation models viz. solar irradiance model, PV array model, maximum power point tracking (MPPT) and direct current (DC) …….