Improvement Method of Optical Fiber Loop Detection in Smart Substation Based on OTDR
[Purposes]During the construction of intelligent substation,to accurately detect non reflective events such as fiber fusion and compression of the fiber optic circuit in intelligent substations,an im-provement method of optical fiber loop detection in smart substation based on OTDR is proposed.[Meth-ods]The clock phase-shifting module is used to perform phase shifting and multiple repeated measure-ments,and then the interpolation and combination of each phase data are performed to obtain a higher sampling frequency.This method significantly improves the sampling accuracy of the optical time do-main reflectometer(OTDR)without increasing hardware costs.At the same time,through wavelet de-noising and sudden variable signal enhancement techniques,noise is suppressed and the wavelet coeffi-cients of event points are highlighted.The useful signals are easier to be detected and the detection level of intelligent substation fiber optic circuits is comprehensively improved.[Findings]After on-site test-ing,the proposed method can accurately detect events such as fiber compression,excessive bending and poor fusion.[Conclusions]Those methods can effectively detect abnormal phenomena of the fiber optic circuit in intelligent substations,prevent hidden defects from affecting the operation of substations,and has great engineering application value.