基于法兰式光纤传感技术的高压组合电器HF气体在线检测

On-line Monitoring of HF Gas in High Voltage GIS Based on Flange Optical Fiber Sensing Technology

SF6气体具有优异的绝缘和灭弧性能,因而广泛应用于高压气体绝缘组合电器(GIS)的生产和使用中,但GIS设备运行状态下的放电和过热故障将导致SF6气体分解生成氟化氢(HF)等多种典型特征气体,因此通过检测高压GIS中HF气体体积分数可有效判断其运行状态。通过提出一种基于可调谐半导体激光吸收光谱检测(TDLAS)和法兰式光纤传感技术的高压组合电器HF气体在线检测方法,即将法兰式光纤传感结构固定安装在GIS管道中,实现了HF气体浓度高精度在线监测。实验数据表明,法兰式光纤传感在线监测装置能够实现对HF气体的有效测量。研究结果表明:盆式绝缘子表面最大场强为11.85kV/mm,低于SF6气体绝缘条件下20kV/mm的场强控制要求,因此盆式绝缘子附近电场不影响光纤传感器运行;在1m光程情况下,HF气体体积分数检出限可达5×10–5以下。研究结果可为高压组合电器SF6气体分解产物在线检测提供一种较为新颖的方案,从而实现对高压GIS内部HF气体的实时在线检测。

Possessing the excellent insulation and arc extinguishing properties, SF6 gas is widely used in the production and operation of the high voltage gas insulator switch-gear(GIS). However, the discharge and overheating faults of GIS equipment will lead to the decomposition of SF6 gas into hydrogen fluoride(HF) and other typical gases. Therefore, detecting the concentration of HF gas in high voltage GIS can effectively judge its operation status. We propose an on-line detection method for HF gas in high voltage combined electrical apparatus based on the tunable diode laser absorption spectroscopy(TDLAS) detection and the flange optical fiber sensing technology. The flange optical fiber sensing structure is fixed in GIS, which can realize high-precision on-line monitoring of HF gas. The experimental results show that the flange fiber optic sensor monitoring device can realize the effective measurement of HF gas. The research results show that the maximum field intensity on the surface of basin insulator is 11.85kV/mm, which is lower than the control field strength of 20kV/mm under the SF6 gas insulation condition. Therefore, the E-field near the basin insulator does not affect the operation of optical fiber sensor. In the case of 1 m light path, the detection limit of HF gas is less than 5×10–5. The results of this study can provide a new scheme for the on-line monitoring of high pressure SF6 gas decomposition products, which can realize on-line monitoring of the internal gas of the high voltage GIS equipment.