为及时发现并判别光纤复合海底电缆的故障, 文章提出一种基于多尺度小波分析的海缆故障检测与诊断新方法。该方法先利用布里渊光时域反射计测量海缆中光纤的布里渊散射频移, 然后结合双阈值法对故障点进行检测和分析。对发生接地故障的数据, 用阈值法进行诊断; 对非接地故障, 则选用coif2小波基进行8尺度小波分解。研究结论表明, 利用小波分解高频系数尺度对空间距离的敏感性可有效诊断锚害和塑料护套局部放电引发的过热故障。同时, 在分析海缆故障特点的基础上, 通过建立海缆故障模拟数据验证了算法的有效性。

In order to timely discover and differentiate the faults in optical fiber composite submarine cables, a novel multi-scale wavelet analysis-based detecting and diagnosing method is proposed in this paper. By this method, the Brillouin scattering frequency shifts in submarine cable fibers are first measured by using a Brillouin optical time-domain reflectometer and then the fault spots are detected and analyzed by using the dual-threshold method. The grounded faults are diagnosed by using the threshold method, but the ungrounded faults are decomposed in 8 scale by using coif2 wavelet basis. The research results indicate that anchor damage and overheating faults caused by partial discharges in plastic sheath can be effectively diagnosed by using the sensitivity of high frequency coefficient scale of wavelet decomposition to spatial distance. On the basis of analyzing the features of submarine cable faults, the effectiveness of this approach is verified by setting up the simulation data of submarine cable faults.