CAJ | 학술논문

高准确度、高灵敏度检测故障特征气体是基于油中溶解气体分析的变压器早期潜伏性故障诊断的关键。基于差频中红外及离轴腔增强吸收光谱技术，搭建了一个变压器油中溶解气体检测系统。以故障混合气体中浓度为0.5μL/L 的C2H4为代表，验证了该系统的检测特性。选取1583.0 nm信号源及1063.8 nm抽运源，利用非线性光学周期极化铌酸锂晶体，结合准相位匹配技术，差频产生了3.245μm(对应C2H4的基频吸收线3081.0016 cm?1)的中红外相干光：最大输出功率为288μW，最大调谐范围为35 cm?1。气体压强100 Torr下，系统对于气体C2H4的最低吸收系数及检测下限分别为7.39×10?10 cm?1及0.0144μL/L，很好地满足了变压器油中溶解乙烯检测极限值(0.5μL/L)的需要，分析和证明了气体压强对C2H4的吸收峰值、系统最低吸收系数及检测下限的影响。该研究结果为基于差频中红外吸收光谱的变压器油中溶解气体带电检测提供了理论依据和技术支撑。
고준학도、고령민도검측고장특정기체시기우유중용해기체분석적변압기조기잠복성고장진단적관건。기우차빈중홍외급리축강증강흡수광보기술，탑건료일개변압기유중용해기체검측계통。이고장혼합기체중농도위0.5μL/L 적C2H4위대표，험증료해계통적검측특성。선취1583.0 nm신호원급1063.8 nm추운원，이용비선성광학주기겁화니산리정체，결합준상위필배기술，차빈산생료3.245μm(대응C2H4적기빈흡수선3081.0016 cm?1)적중홍외상간광：최대수출공솔위288μW，최대조해범위위35 cm?1。기체압강100 Torr하，계통대우기체C2H4적최저흡수계수급검측하한분별위7.39×10?10 cm?1급0.0144μL/L，흔호지만족료변압기유중용해을희검측겁한치(0.5μL/L)적수요，분석화증명료기체압강대C2H4적흡수봉치、계통최저흡수계수급검측하한적영향。해연구결과위기우차빈중홍외흡수광보적변압기유중용해기체대전검측제공료이론의거화기술지탱。
ABSTRACT:A highly accurate and sensitive detection of fault characteristic gases is the key to diagnosing incipient transformer faults through dissolved gases analysis. In this paper, based on mid-infrared difference frequency generation and off-axis cavity enhanced absorption spectroscopy technology, a detection system for dissolved gases in transformer oil was built up. The C2H4with concentration of 0.5μL/L in multiple fault gases dissolved in transformer oil was taken as a representative to verify the detection characteristics of this system. Combined with quasi-phase- matched (QPM), the signal source (1583.0nm) and pump source (1063.8nm) had been adopted in a compact and fibre- coupled periodically poled lithium niobate (PPLN) waveguide module, generating 288μW of 3.245μm wavelength laser light with a wide tunability range of 35cm?1. The wavelength of 3.245μm is corresponded to fundamental frequency absorption line 3081.0016cm?1 of C2H4. The lowest absorption coefficient and detection limit of this system for C2H4 is 7.39×10?10 cm?1 and 0.0144μL/L at gas pressure of 100Torr respectively, which well satisfies the requirement of detection limit (0.5μL/L) for C2H4dissolved in transformer. The effects of gas pressure on the absorption peak value, lowest absorption coefficient and detection limit of system for C2H4 were also analyzed and demonstrated. This provides theoretical basis and technical support for transformer oil-dissolved gases live detection based on mid-infrared absorption spectroscopy with difference frequency generation.