Electric Field Characteristics Research Of Power Transmission Structure Of Spacecraft Based On Space Charging And Discharging Effect

The spacecraft running in space environment, will encounter a variety of space environment factors, in which the space charged particle has most significant effect on the spacecraft. The resulting space charging and discharging effect is one of the important reasons of satellite faults. As the important part of the satellite power system, power transmission structure easily becomes the infringed object of the charging and discharging effect. Once it breaks down, the satellite goes wrong. In recent years, with the wide application of high voltage power spacecraft energy system, the requirement of design, manufacture and protection of energy system is also increasing day by day. Aiming at the charging and discharging effect of power transmission structure, this paper adopts the method of combining the numerical simulation and experimental research, launches the research work from two aspects of material level and component level, and puts forward optimization measures in the design, manufacture and protection.The nature of space charging and discharging effect is the interaction theory between space charged particles and spacecraft materials. Based on the charged particle damping mechanism and the Monte Carlo statistical method, taking commonly used material by the power transmission structure-aluminum and polyimide as the research object, this paper analyzed the transport characteristic, the deposition characteristic and the energy decrement of the incident particles in the material by the particle transport simulation software such as GEANT4. Then based on deep charging model and radiation induced conductivity model, the theoretical analysis is performed for radiation induced conductivity properties and electric field characteristic within the material.Power transmission structure of spacecraft is complex, including high power conductive ring components and insulation materials, thus making it true that there is a big risk of charging and discharging effect. By the secondary development software of GEANT4, taking the simplified model of power transmission structure as the research object, this paper simulated the electric field characteristics in the structure irradiated by the electron beam, and analyzed the influence of energy of incident particles and geometric parameters on the result of the charging effect. Finally, the deep charging experimental platform was set up by electron beam radiation on power transmission structure surface. In the experimental process, the surface potential of insulation material was measured and analyzed under three different conditions including ground condition, high voltage condition and suspension condition. The experiment was also to verify the correctness of simulation results.The results showed that insulating material conductivity is one of the important factors to determine whether material discharge occurs. The energy of incident particles and geometric parameters have marked impact on the result of charging effect. The working voltage of power transmission structure can offset the charging voltage. Try to make the insulation material of power transmission structure ground, which helps to reduce the risk of charging and discharging effect.