Multiple Faults Location and Evaluation in Shielded Cable Based on Joint Analysis of Reflection Coefficient Spectrum and Matched Filter Matrix

In industrial systems, cables are used to connect various pieces of equipment. Diagnosing soft faults in cables is a consistent step to ensure the system's stable operation. The bottleneck with existing diagnostic methods is locating and evaluating multiple faults in a cable with low error. In this article, a novel fault diagnosis method is proposed to locate multiple faults and estimate their reflection coefficients; the latter is used to assess the level of the fault. First, the reflection coefficient spectrum (RCS) (the data to be processed) is modeled, the relationship with faults is elaborated, and cable model parameters are estimated. Second, a matched filter matrix is constructed to analyze the RCS to locate faults. Third, the compensation model based on the cable transfer function is constructed to compensate for the attenuation of the signal and then estimate the reflection coefficients. Finally, sidelobe analysis is performed to improve detection accuracy, and multiple reflection analysis is performed to elaborate on the complex reflection phenomenon between multiple faults and filter out their interference in detecting real faults. Experimental results show that the proposed method locates multiple faults, estimates reflection coefficients with low error, and exhibits good robustness in the presence of noise.