太赫兹信号在老化硅橡胶中的传播特性仿真研究

Simulation study on propagation characteristics of terahertz signal in aging silicone rubber

绝缘是影响电力系统稳定运行的重要因素,但大多数情况下电气设备很难拆卸,对其绝缘老化程度的检测较为困难。太赫兹波具有可以轻易穿透绝缘材料等非金属材料的特性,这对于硅橡胶复合绝缘子的无损检测具有重要意义。分析了太赫兹信号在理想介质与有损介质中传播的特性,从理论上阐述了其在非理想材料中可能发生的损耗,进而指出可以通过检测太赫兹回波损耗变化来反映硅橡胶介电常数的变化及其老化程度。之后在CST仿真软件上搭建仿真模型,改变材料的相对介电常数以及太赫兹信号的频率,研究其对回波损耗造成的影响,最后得出的结论可以更有效率地指导实际实验的进行。

Insulation is an important factor affecting the stable operation of power system, but it is difficult to disassemble electrical equipment in most cases, and it is difficult to detect the aging degree of insulation. Terahertz wave can easily penetrate non-metallic materials such as insulating materials, which is of great significance for nondestructive testing of silicone rubber composite insulators. the propagation characteristics of terahertz signal in ideal and lossy medium are analyzed, and the possible loss of terahertz signal in non-ideal materials is described theoretically. Furthermore, it is pointed out that the change of permittivity and aging degree of silicone rubber can be reflected by detecting the change of terahertz return loss. After that, the simulation model was built on the CST simulation software, and the relative dielectric constant of the material and the frequency of the terahertz signal were changed to study the influence on the return loss. Finally, the conclusion could guide the actual experiment more efficiently.