基于布里渊光时域峰值边沿分析的变压器绕组局部热点检测  

Local Hot Spot Detection of Transformer Windings Based on Brillouin Optical Time Domain Peak Edge Analysis

作　　者：刘云鹏[1] 黎晏霖 李欢[1] 范晓舟[1] Liu Yunpeng;Li Yanlin;Li Huan;Fan Xiaozhou(Hebei Provincial Key Laboratory of Power Transmis-sion Equipment Security Defense,North China Electric Power University,Baoding,071003,China)

机构地区：[1]华北电力大学河北省输变电设备安全防御重点实验室,保定071003

出　　处：《电工技术学报》2024年第11期3486-3498,共13页Transactions of China Electrotechnical Society

基　　金：国家电网公司科技项目资助(5206002000D6)。

摘　　要：变压器绕组的温度分布一直是电网运行人员重点关注的对象。与传统传感器相比,分布式光纤传感具有抗电磁干扰能力强、可实现分布式测量等优势,其中布里渊光时域分析技术(BOTDA)的性能稳定,适用于大多数场景,但BOTDA的空间分辨率为m级,难以分辨绕组运行中的局部热点。该文从布里渊散射增益谱的机理入手,利用双峰拟合算法,并结合对异常峰值曲线的边沿分析,提出了一种在不增加系统硬件复杂度的基础上提升BOTDA空间分辨率的方法,以满足局部热点检测要求。通过对光纤沿线不同位置、不同热点长度及不同热点温度下的模拟试验验证了该方法的有效性,在实验室条件下可将准确传感的热点长度提升至原空间分辨率的一半以内。基于变压器实际绕组的局部升温试验,实现了绕组异常热点的精确定位和长度感知,并准确解调了绕组局部热点的温度,进一步验证了该方法的实际可行性和检测优越性,温度相对误差控制在5%以内,为提高变压器绕组温度在线监测的经济性和可行性提供新的思考,同时也为变压器绕组局部故障的提前感知和预警提供了新的思路。The temperature distribution of transformer windings has always been the focus of power grid operators.Compared with traditional sensors,distributed fiber sensing has great advantages such as strong anti-electromagnetic interference ability and distributed measurement.Brillouin optical time domain analysis(BOTDA)has stable performance and is suitable for most scenarios.However,the spatial resolution of BOTDA is on the order of meters,making it difficult to distinguish local hot spots in winding operation.Starting from the mechanism of Brillouin scattering gain spectrum,this paper proposes a Brillouin optical time domain peak edge analysis(BOTDA-PEA)technique to improve the spatial resolution of BOTDA without increasing the complexity of the system hardware by describing the bimodal fitting principle and analyzing the edge of the abnormal peak intensity curve in the disturbed fiber,so as to meet the requirements of local hot spot detection in transformer windings.The basic principle of this technology is that when the length of the disturbed fiber is less than the spatial resolution,the hot spot is precisely located according to the descending edge of the subpeak scattering intensity curve,the traditional fitting results are modified according to the corresponding Brillouin frequency shift of the subpeak,and the actual hot spot temperature is demodulated.Firstly,three sets of simulation experiments were designed under laboratory conditions to study the performance of BOTDA-PEA in terms of different locations,different hot spot lengths and different hot spot temperatures along the fiber.When the length of the disturbed fiber segment was less than the spatial resolution of BOTDA,the influence of different variables on the Brillouin gain spectrum is obtained by using the control variable method.The experimental results verify that the position corresponding to the declining edge of the subpeak intensity curve in the bimodal region of Brillouin scattering spectrum is the exact position of the disturbed fiber segment,a

关 键 词：光纤传感 变压器 绕组热点温度 布里渊光时域分析技术 空间分辨率 

分 类 号：TM41[电气工程—电器]