Research on Deep Dielectric Charging Characteristics and Insulation Optimization of Aerospace Electric Brush Plates

In the extreme electronic radiation environment of space, high-energy electrons can cause deep dielectric charging of the insulation components of the electric brush plate, causing discharge of the insulation medium and adjacent electric brushes, thereby inducing insulation failure of the solar array drive assembly (SADA), and even leading to the failure of the entire satellite. The material of the insulating medium, the state of the electric brushes, and the distance between the electric brushes can directly affect the discharge threshold of the electric brush plate. Therefore, it is necessary to conduct in-depth research on these factors in order to reduce the possibility of discharge accidents. To this end, a 3-D deep charging model of the insulation component of the electric brush plate was established, and the 3-D distribution of the electric field and potential of the insulation component of the electric brush plate was obtained. The time characteristics of deep dielectric charging of the electric brush plate were studied. After stopping electron irradiation, the electric brush plates remained at a potential of over 5 kV for a long time, posing a risk of discharge. The study investigated the effect of material composition on deep dielectric charging of electric brush plates, and the results showed that the electric brush plate with the highest conductivity, consisting of 60% YS $20+30$ % ZnO +5% GF +5% POSS material, has the strongest electric charge bleed ability. Further based on the distribution of deep dielectric charging potential on the electric brush plate, the ME-268A flat charge meter was used to verify that the 60% YS $20+30$ % ZnO +5% GF +5% POSS material composition electric brush plate has good charge transport characteristics and insulation performance, and the influence of electric brush state and electric brush distance on charging voltage was studied. The results indicate that insulation measures, such as increasing the installation distance of adjacent electric brushes, chamfering the electric brush ends, and coating the electric brushes with insulation coatings, can improve the electrostatic protection ability between adjacent electric brushes.