非平衡态双温度SF_6等离子体电弧数学模型研究

Non-equilibrium Dual Temperature SF_6 Plasma Arc Mathematical Model Research

笔者针对SF6断路器小电流开断过程中温度梯度、各粒子密度梯度较大等现象,对非平衡态等离子体双温度电弧模型进行研究。分析电子与离子及中性粒子的碰撞频率与碰撞截面对电导率的贡献,得到SF6等离子体电导率随温度和压力变化关系,进而建立小电流条件下非平衡态双温度电弧模型。在已建立小电流非平衡态双温度电弧模型基础上,将研究结果应用于126 kV SF6断路器开断容性小电流弧后介质恢复特性计算,得到计算结果与平衡态条件下相比是有差异的,此电弧模型的建立为非平衡态小电流数值计算提供了一种新的方法,研究结果对完善电器电弧理论具有重要意义。

Aiming at the phenomenon that the gradients of temperature and particle density are bigger in the breaking process of small current for SF6 circuit breaker, this paper has conducted a study on the non-equilibrium plasma dual temperature arc model. Considering the contribution of electron-ion-neutral particle collision frequency and collision cross-section, the plasma conductivity as a function of temperature and pressure can be obtained, and then the non-equilibrium dual-temperature arc model for small capacity current is built. Based on the established arc model, the research results are applied to the calculation of post-arc dielectric recovery characteristic of small capacitive current for a 126 kV SF6 circuit breaker, and the results differ from that calculated under equilibrium conditions. This arc model provides a new method for the numerical calculation of non-equilibrium small current and the research achievements are of great significance to perfect the theory of electric arc.