Abstract:

A quasi-Sun-pointing (QSP) oriented attitude is proposed for pitch attitude motion of the solar power satellites, which can chase the movement of the Sun. With less control effort, the solar arrays oscillate around the direction perpendicular to the Sun under the influence of the gravity gradient torque, with the amplitude of 18.8°. The main contribution is solving the enormous pitch attitude control moment problem for the large solar arrays. The power generation efficiency of the QSP oriented attitude is 97.3% of that of the Sun-pointing attitude. However, it saves about 36791 kg fuel per year for the Abacus solar power satellite. The accurate initial attitude conditions of the QSP attitude are obtained through the numerical method. Then, a proportional-derivative controller is designed to guarantee the convergence of the QSP attitude. Finally, the effects of the orbital motion, attitude motion, and structural vibration on the QSP attitude are studied. It is found that the QSP oriented attitude also contributes to reduce the structural vibration of the solar arrays by about 40 times.

Key words: Solar power satellite, Gravity gradient torque, Quasi-Sun-pointing (QSP) oriented attitude, Attitude control