SF6局部放电分解组分长光程红外检测

摘要

A close relationship is existed between SF6 partial discharge decomposition components and the insulation condition in gas insulated switchgear（GIS）. Monitoring the decomposition components can diagnose the insulated defect of GIS. The SF6 partial discharge decomposition components are low concentration. To enhance the detection limit, a long optical path gas cell is designed based on the White cell, and the essential parts of the equipment are three conjugated spherical mirrors, which gained long optical paths by the light＇s multiple reflections in it, reducing the energy dissipation while increasing the optical paths, 20 meters optical length gas cell matching with Fourier transform infrared spectroscopy （FTIR） is developed. Long and short optical paths gas-cells are used to detect the SF6 partial discharge decomposition components. It＇s found that the 20 meters＇ optical length gas cell＇s spectrum has a great gas species, high degree of accuracy and signal-to-noise ratio. 20 meters gas cell can fulfill SF6 partial discharge decomposition components＇ quantify research.%GIS内SF6局部放电分解组分情况与其绝缘状态有着密切联系，监测分解气体组分可诊断出GIS内部的绝缘缺陷。由于sF6分解产物浓度很低，为提高检测限，基于怀特池原理，利用三个凹面反射镜组成共轭系统来实现光路的多次反射，在有效地增加了光程长的同时尽量减少了光能损耗，设计了与傅里叶变换红外光谱仪匹配的20m光程长气体池。分别用长短光程气体池进行SF6局部放电分解组分的红外检测，对比分析发现，20m长光程气体池检测组分种类多，精度和信噪比高，设计的长光程气体池可以实现GIS内部SF6局部放电分解组分的定量研究。