基于质谱-光谱联合分析的真空沿面闪络中聚合物材料的降解现象、规律及机理研究

The surface flashover phenomenon in vacuum is a common problem of vacuum insulation in multiple fields. The present theories in vacuum surface flashover are mostly reasoning or hypothesis based on special experimental phenomena, in which the general verification of systematic and effective experiment is deficient. Furthermore study on the degradation of insulation material in vacuum surface flashover is quite few. We'll begin the study from the degradation phenomenon of polymeric materials in vacuum surface flashover. The out-gassing characteristic of insulation surface and the spectral composition of the flashover light emission are measured in different stages of discharge development by mass spectrometry and optical spectrum analysis. The degradation regularity and mechanics of polymeric materials in vacuum surface flashover will be obtained and the effect of different theories in the discharge development will be verified in experiment and measurement. The degradation characteristic and regularity of polymeric materials are studied based on a large quantity of surface discharge experiments in vacuum. Simultaneously the out-gassing measurement and the surface discharge experiment of polymeric materials are also developed in different induction factors. The microscopic structure and parameter of polymer surface are obtained by surface analysis and measurement, and their relation to the macroscopic parameter attributing the dielectric and aging performance is studied. Combined with the trap theory in polymer aging and simulation study on microscopic process of vacuum surface flashover, the degradation mechanics of polymeric materials will be discussed. The surface flashover theories in vacuum involving the development in the body or in the desorption gas will be well established. The research production can be used to guide the insulation design and surface modification in vacuum and is also the basis of condition monitoring and fault diagnosis of vacuum devices.

真空沿面闪络是多领域真空绝缘中面临的共性问题。现有的真空沿面闪络理论多是基于实验现象的推理与假设，缺乏系统有效实验数据的全面验证；同时对于真空闪络中材料的分解现象研究很少。本课题从真空沿面闪络中聚合物材料的降解现象出发，采用质谱-光谱联合分析的手段研究真空沿面放电不同发展阶段材料表面的出气特性及发射光谱特性，获得聚合物材料在真空闪络中的分解规律及分解机制，获得不同理论在闪络发展中所起作用的实验验证。基于真空沿面闪络的大量实验及不同诱导因素下材料出气及闪络的实验数据，研究真空闪络中及不同因素作用下材料的分解特性及规律；采用表面分析及测量技术，研究材料表面的微观结构及参量与表征材料介电及老化性能的宏观参量之间的关系；结合聚合物老化的陷阱理论及真空沿面放电微观过程的仿真研究，深入探讨聚合物材料在闪络中的分解机理，完善真空沿面放电的体内及体外发展理论。

真空沿面闪络是脉冲功率、传统高压、高功率微波及航天等多领域真空绝缘中面临的共性问题，其有效地解决对于改善和提高真空器件的性能，保证关键设备的安全运行具有重要的意义。本课题从真空沿面闪络中聚合物材料的降解现象出发，采用质谱-光谱联合分析的手段研究真空沿面放电中材料表面的出气特性及发射光谱特性，采用等温电位衰减法研究陷阱参数在真空闪络中所起的作用，获得聚合物材料在真空闪络中的分解规律及分解机制，获得不同理论在闪络发展中所起作用的实验验证。基于不同电压形式下真空沿面闪络的大量实验，以及离子注入、等离子体处理、电子束辐照及表面粗糙度改变等不同诱导因素作用下聚合物材料的闪络实验数据，获得真空闪络中不同聚合物材料的分解特性及不同因素作用下的真空沿面耐压特性。研究结果表明，不同诱导因素改变了绝缘材料表面的粗糙度、陷阱参数及二次电子发射系数等参数，进而改变了其真空闪络性能；聚合物材料在预放电阶段即发生分解现象，分解产物参与后续的真空沿面闪络过程；真空闪络中产生气体的总量和种类和聚合物材料的结构及性能有关。采用表面分析及测量技术，研究材料表面的微观结构及参量与表征材料介电及老化性能的宏观参量之间的关系，获得聚合物表面的微观形貌、电荷积聚及陷阱参数对其真空沿面耐压的影响规律。在质谱-光谱联合分析真空闪络出气特性及发射光谱的基础上，结合聚合物老化的陷阱理论及真空沿面放电微观过程的分析，探讨聚合物材料在闪络中的分解机理，指出聚合物的分解同样受绝缘表面的自由基反应及绝缘表面层内的陷阱电荷及热电子效应共同影响。本项目的研究成果对多领域真空绝缘中材料的选型、改性及真空设备的性能提高及安全运行均有重要的指导意义。