无需油气分离的油中溶解乙炔原位直接检测  

Direct Detection of Oil-dissolved Acetylene Without Oil-gas Separation

作　　者：王渊 马国明 谢洋洋 陈章霖 郑迪雅 秦炜淇 WANG Yuan;MA Guoming;XIE Yangyang;CHEN Zhanglin;ZHENG Diya;QIN Weiqi(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《中国电机工程学报》2023年第20期8151-8160,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51977075);中国科协青年人才托举工程(YESS20160004);霍英东教育基金会高等院校青年教师基金(161053)。

摘　　要：现有变压器油色谱技术检测存在时效性差、传感元件无法内置于变压器内部、油气分离时间长等问题,该文提出一种基于光子晶体光纤的油中溶解乙炔光热光谱直接检测方法。通过在光纤表面加工尺寸仅为3μm×3μm、且深至芯区的微通道以及光传输损耗低至3.1dB的光纤熔接等方法,研制出可实现激光在油中低损耗传输的油芯光子晶体光纤。理论推导泵浦光导致的光子晶体光纤内温升分布情况,探索探测光相位与油中乙炔含量的关联关系。提出基于外差干涉的油中乙炔光热光谱传感拓扑,在干涉结构传感臂引入光纤环腔,提升了检测灵敏度。此外,提出双泵浦光波长差分降噪方法,可有效降低变压器运行现场噪声对乙炔检测结果的严重干扰。成功实现无需油气分离的油中痕量乙炔高灵敏度、高可靠性检测,检测下限达1.4μL/L。开展变压器油中放电分解乙炔高电位原位实时检测,试验结果表明,所研制的油中溶解乙炔光热光谱检测系统可大幅提高变压器诊断的时效性。The existing transformer oil chromatography techniques have problems such as poor detection timeliness,the sensor element not being able to be built in the transformer,and the long oil-gas separation time.In this paper,a novel monitoring method for oil-dissolved acetylene based on photonic crystal fiber and photothermal spectroscopy is proposed.By processing microchannels with a size of only 3mm×3mm and deep to the core region on the surface of the photonic crystal fiber,and fiber fusion splicing with an optical transmission loss as low as 3.1dB,an oil-core photonic crystal fiber(OC-PCF)that can realize low-loss transmission of laser in oil is developed.The distribution of the temperature rise in the photonic crystal fiber caused by the pump light is theoretically deduced,and the correlation between the phase change of the probe light and the concentration of the oil-dissolved acetylene is mastered.A photothermal spectroscopy sensing topology of oil-dissolved acetylene based on heterodyne interference is proposed,and the detection sensitivity is improved by introducing a fiber-loop cavity into the sensing arm of the interferometer.A dual pump-wavelength differential noise reduction method is proposed.It effectively reduces the serious interference of the in-situ noise to the acetylene detection.The high-sensitivity and high-reliability detection of trace oil-dissolved acetylene without oil-gas separation is achieved,and the minimum detection limit is about 1.4mL/L.The high-potential in-situ real-time monitor of the oil-dissolved acetylene is carried out.The actual measurement results show that the developed photothermal spectroscopy detection system for oil-dissolved acetylene can greatly improve the timeliness of transformer diagnosis.

关 键 词：油中溶解乙炔 油芯光子晶体光纤 光热光谱 原位检测 无需油气分离 

分 类 号：TM41[电气工程—电器]