中文摘要：

屏蔽罩电位是判断真空断路器灭弧室真空度水平优劣的一种技术手段,研究人员对屏蔽罩电位信号成分及其形成机理进行了大量的研究工作,并在理论上和试验方面取得了一定成果。但对于真空屏蔽罩上电位的成因并无公认的解释,且实际应用中难以将不同型号的断路器按同一标准对待。为寻求真空度与屏蔽罩电位的内在联系机理,本文基于前人研究成果,从电介质学及气体放电的相关理论出发,将真空度劣化过程分成三个阶段分别讨论,阐述了各个阶段依据理论基础。特别针对真空度高于0.1 Pa时较难判断的屏蔽罩电位值,利用有限元分析的方法进行了3D电场计算,分析了该真空度范围下屏蔽罩电位的变化规律,研究成果提供了一种真空度判断与评估的可行方法,具有较好的应用参考价值。

英文摘要：

Abstract Here, we addressed the relationship between the shield potential and the internal pressure of the vacuum circuit breaker in the three phases of the pressure building-up, based on electromagnetic theory, gas discharge theory, and the published results in the literature. The dependence of pressure on the dielectric constant of the residue gases was evaluated. The shield potential, especially when the pressure in the vacuum interrupter is lower than 0.1 Pa, was modeled, approximated, and calculated in three-dimension finite element method. The calculated results show that in the pressure range below 0.1 Pa, as the pressure increases, the A. C. shield potential increases with an amplitude up to 2 V; whereas at a pressure above 0.1Pa, the shield potential turns into a D. C. potential.