直流均匀电场SF6气体电流密度改进数学模型研究

在直流均匀电场下,SF6气体的电流密度可分为欧姆电导区、饱和电流区和电流激增区。传统欧姆电导区和饱和电流区的数学模型忽略了空间复合和极板复合同时存在的微观过程,电流激增区数学模型由于电离系数随着温度、气体种类等的动态不稳定而在应用中受限。因此,考虑离子产生、空间迁移、空间复合、扩散及碰撞电离等微观过程,提出了SF6气体直流电流密度的改进数学模型,并对传统模型和改进模型的三区分界电场强度进行了仿真计算。结果表明,改进模型的计算结果更符合电流密度分区的定义。

Research on Improved Mathematical Model for SF6 Gas Current Density in DC Uniform Electric Field

Under the uniform DC electric field, the current density of the SF6 gas can be divided into three areas: the ohm conductance area, the current saturation area and the current surge area. The mathematical model of the traditional ohmic conductance area and saturation current area ignores the microscopic process of both spatial recombination and plate recombination. The mathematical model of the current surge area is limited in application due to the dynamic instability of the ionization coefficient with temperature, gas species and so on. Considering the microscopic processes of ion generation, space migration, space recombination, space diffusion, and collision ionization, this paper proposes the improved mathematical model of DC current density of SF6 gas. The three-area demarcation electric field strengths of the traditional model and the improved model are simulated. The results show that the improved model accords with the definition of the current density partition.