航天器表面电荷激发空间静电场规律研究

Study on Distribution of Electrostatic Field Induced by Spacecraft Surface Charge

从带电表面微元出发,通过求解泊松方程,得到带电介质平板表面邻近空间静电势的解析表达式,建立介质表面电位-介电常数模型,求得了带电介质平板表面电位、表面带电量和介质介电常数三者之间的关系式。结合典型的航天器表面介质材料带电案例,对此类圆盘结构介质平板带电问题进行了仿真分析,结果表明,在介质材料表面电位一定的情况下,表面电荷激发的空间静电势值随距离的增大而减小,并且距离介质表面越近,电势的空间变化率越大;在介质材料带电量相等的情况下,介质表面电位随着介质介电常数的增大而减小,并逐渐趋于一个稳定值,所以在一定范围内选择介电常数较大的介质材料可以降低介质的表面电位,减小介质间发生静电放电的几率。

The analytic expression of the electrostatic potential near the spacecraft surface is obtained by solving the Poisson equation based on the electrostatic field theory,and the mathematical expression of the electric field intensity near the spacecraft surface is deduced.Using the boundary condition of the electromagnetic field,the dielectric surface potential-permittivity model is established,and the relationship among the dielectric surface potential,surface charge and permittivity is gained.Taking the practical cases for example,the change regulation of the surface charge with surface potential and the distribution of the electrostatic field near the spacecraft surface is discussed,and the effect of the dielectric constant on the surface charge and surface potential is analyzed.The results show that the electrostatic field induced by the dielectric surface charge decreases as the distance incrases when the surface potential of media is constant,and the surface potential of media decreases with the increase of the dielectric permittivity and tends to a stable value under the condition that the dielectric material has equal charge.Therefore,it is possible to select the dielectric materials with smaller permittivity under certain conditions to reduce their surface potential,and to reduce the probability of the electrostatic discharge between different media.