随着电力系统向高压、 大容量、 信息技术应用等方向发展, 电力设备的高效运维对于保障电力系统安全运行和经济平稳增长具有重大意义。 对六氟化硫气体分解产物的检测是电气绝缘设备检漏及判断故障类型的有效手段。 基于光学频率梳的双光梳光谱检测技术具有高分辨、 高精度、 宽光谱、 高速动态等优势, 有望在电力设备漏气故障检修中, 为判断特征气体种类及定量分析提供可靠手段。 搭建了基于两台集成掺铒光纤光梳的双光梳光谱检测装置。 通过精密频率控制及精细温控, 光梳重复频率抖动从18.37 Hz降低至607.72 μHz, 光梳梳齿稳定度控制在10-12。 装置具有长时间稳定和小型化集成的特点, 对外界环境干扰免疫性强, 在室外环境运行两小时, 光梳的重复频率及载波包络相位信号仍能保持相位锁定, 两台光梳相干性无明显劣化。 在光谱检测方面, 结合使用超灵敏多通气室, 对CO与CO2混气进行了测量, 在ms量级时间内实现了1 540～1 590 nm波段内CO和CO2吸收峰的同时成谱检测, 光谱分辨率达1 pm。 分别以CO和CO2在1 585.47、 1 581.946 nm和1 580.5、 1 579.575 nm的特征吸收峰为例, 通过洛伦兹数据拟合反演出相应分子数密度。 CO和CO2的气体分子数密度的多峰测量不确定度分别为0.32%与0.24%, 较单峰测量结果(2%)降低了近1个量级。 该研究推进了双光梳光谱技术及系统在电力设备漏气故障特征气体非接触实时检测中的应用。 传统接触式检测存在检测气体种类单一、 积分时间长、 难以做到长期在线实时监测的缺点, 而双光梳光谱检测能够在ms量级对多组分气体的多峰非接触式同时成谱检测, 在缩短检测时间的同时提高了检测精度, 为电力设备漏气故障的及时排查及故障类型的诊断提供了有效途径。

With the rapid development of power systems towards high voltage, large capacity and application sininformation technology, the efficient operation and maintenance of power equipment is of great significance to ensure the safe operation of power systems and steady economic growth. Detecting sulfur hexafluoride gas decomposition products is an effective method for leak detection and fault diagnosis in electrical insulation equipment. Dual-comb spectroscopy, derived from optical frequency combs, has the advantages of high resolution, high precision, wide spectrum and high speed, and is expected to provide a reliable method for quantitative analysis of characteristic gases in leakage troubleshooting of power equipment. In this paper, a dual-comb spectroscopy detection equipment was built by using two integrated erbium-doped fiber optical combs. With precise frequency control and fine temperature control, the frequency fluctuation of the repetition rate was decreased from 18.37 Hz to 607.72 μHz and the stability of the comb teeth was improved to 10-12. The long-term stability and integration enabled the combs strong immunity to environmental disturbance and the combs maintained high coherence within more than 2 hours in outdoor operation as the repetition rate and the carrier envelope phase offset signals of the combs kept phase-locked. In terms of spectral detection, the mixture of CO and CO2 was measured with the help of an ultra-sensitive multi-pass cell and as a result, the absorption peaks of CO and CO2 within the 1 540～1 590 nm band were simultaneously measured with 1 pm spectral resolution on the ms time scale. Taking the characteristic absorption peaks of CO at 1 585.47, 1 581.946 nm, and CO2 at 1 580.5, 1 579.575 nm, for example, the molecular densities of CO and CO2 could be easily derived from Lorentzian fitting, and the uncertainties were reduced to 0.32% and 0.24%, respectively, using multi-peaks fitting, which were nearly one order of magnitude lower than that of single-peak measurement (2%). Our research promotes the application of dual-comb spectroscopy and the related system in non-contact real-time detection of characteristic gases in power equipment. Compared with the traditional contact detection technology, which has the shortcomings of single gas detection, long integration time, and difficulty in long-term online real-time monitoring, the dual-comb spectroscopy is advantaged in simultaneously multi-peaks detection of diverse gases in ms order of time, which can shorten detection time and improve the accuracy. In a word, dual-comb spectroscopy provides an effective method for timely troubleshooting and fault diagnosis for leak detection in power equipment.