Study on Surface Charging Effect and Electric Field Distribution of Spacecraft Solar Array in Low Earth Orbit

In the Low Earth Orbit (LEO) plasma environment, primary discharge may occur on high-voltage solar array, which affects the insulation performance and normal operation, and threatens the safe operation of the spacecraft. Based on the current balance equation, a three-dimensional surface charging model is established by using the Particle In Cell (PIC) method and the equivalent circuit method. Considering the three typical potential positions of the solar array, the surface charging under different working conditions is simulated and analyzed. The results show that with the increase of the operating voltage of the spacecraft solar array, the surface charging potential is more negative, and the electric field distortion at the triple junction mainly occurs between the coverglass side and the silver interconnect, and between the silver interconnect and the substrate. The maximum electric field intensity can reach$4.36 \times 10^{7} \mathrm{V} / \mathrm{m}$, and the risk of breakdown discharge is extremely high. This study can provide important theoretical guidance and technical support for researching and evaluating the primary discharge risk of spacecraft solar array.