基于时频域反射法的核电站仪控电缆缺陷检测  

Defect detection of I&C cable in NPP based on TFDR

作　　者：王志武 涂画 李力行 邓红雷[2] WANG Zhiwu;TU Hua;LI Lixing;DENG Honglei(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou 215004,China;School of Electric Power,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]苏州热工研究院有限公司,江苏苏州215004 [2]华南理工大学电力学院,广东广州510640

出　　处：《电力工程技术》2023年第5期240-249,共10页Electric Power Engineering Technology

摘　　要：为确保核电站中仪控电缆的安全运行,时频域反射法(time-frequency domain reflectometry,TFDR)被广泛用于识别和定位仪控电缆中的缺陷。文中对比魏格纳-维利分布(Wigner-Ville distribution,WVD)、伪魏格纳-维利分布(pseudo Wigner-Ville distribution,PWVD)、平滑伪魏格纳-维利分布(smooth pseudo Wigner-Ville distribution,SPWVD)算法的优势,并提出时频域互相关曲线(time-frequency cross-correlation,TFCC)的能量区间放缩法。分别对50 m和148 m的多芯交联聚烯烃仪控电缆进行短路、断路、绝缘屏蔽层破损和局部热老化的缺陷模拟,并基于TFDR,采用3种时频分布算法进行实验处理。随后,基于局部热老化的检测,采用能量区间放缩法,对TFCC定位峰主瓣较宽的问题进行改善。实验结果表明:经过SPWVD处理后,TFCC的主瓣较宽;在正常电缆检测时,PWVD对交叉项有更好的抑制作用;但在单缺陷检测中,SPWVD具有更好的缺陷识别能力;通过采用能量区间放缩法,可分离相近的定位峰,加强对微弱反射信号的判别。To ensure safe operation of instrumentation and control(I&C)cables in nuclear power plants(NPP),time-frequency domain reflectometry(TFDR)is widely applied to identify and locate typical defects in I&C cables.The advantages of Wigner-Ville distribution(WVD),pseudo Wigner-Ville distribution(PWVD),and smooth pseudo Wigner-Ville distribution(SPWVD)are compared.In addition,the energy range scaling method is proposed in the time-frequency cross-correlation(TFCC)processing.During the experiment,a 50-meter and a 148-meter multi-core cross-linked polyolefin I&C cable are prepared to simulate several failure cases,including short circuit,open circuit,metal shield damage,and local thermal agingdefect.Based on the TFDR method,three time-frequency distribution algorithms are adopted.Then,the energy range scaling method is applied to improve the problem of wide main lobe of TFCC localization peak.The experimental results show that the main lobe of TFCC is wider after SPWVD processing.PWVD has a better inhibitory effect on cross terms in normal cable detection.In terms of detecting a defect,SPWVD has better detection ability.By using the energy range scaling method,similar localization peaks can be separated to enhance the discrimination of weak reflection signals.

关 键 词：仪控电缆 缺陷检测 故障定位 时频域反射法(TFDR) 时频分析 时频互相关曲线(TFCC) 

分 类 号：TM247[一般工业技术—材料科学与工程]