Detecting SO2 and CF4 under high concentration SF6 Using V-shaped Cavity Enhanced Raman Spectroscopy

As an important and widely used electrical equipment, GIS (gas insulated switchgear) greatly affects the stability and safety of the entire power grid. By detecting the concentration of SF 6 decomposed component gases in GIS, we can judge the faults existing in the GIS, and prevent the corrosive decomposed gases from damaging the insulation. However, existing SF 6 decomposition component detection methods can are difficult to achieve relatively accurate simultaneous detection of multi-component gases. In this paper, a method using cavity enhanced Raman spectroscopy was developed to simultaneously detect SO 2 and CF 4 under high concentration SF 6 . Based on frequency-locking cavity enhancement technology, we coupled laser light with a wavelength of 642 nm and a power of about 50 mW into a V-shaped resonant cavity, and realized three orders of power enhancement. Due to the special V-shaped structure of the resonant cavity, the direct reflected light from the cavity mirror will not feedback to the laser, thereby avoiding false locking. Under 1 atmosphere pressure, Raman spectroscopy of CF 4 and SO 2 with a concentration of 1% was obtained. The characteristic Raman spectral lines of CF 4 and SO 2 were determined as 909 cm−1 and 1151 cm−1, respectively. responding to their v1 transition. And the Raman spectrum of CF 4 and SO 2 under the pressure of gradient distribution was obtained, it was found that the Raman characteristic peak intensity of CF 4 and SO 2 was highly linear between pressure relationship. Besides, the mixed gas of CF 4 and SO 2 under high concentration SF 6 was detected simultaneously without any interference. This study laid the foundation for Raman spectroscopy for the detection and quantitative analysis of SF 6 decomposed gas components, indicating that Raman spectroscopy has great potential in the field of SF 6 decomposed gas component detection.