An Improved Algorithm of Cable Fault Diagnosis Considering Signal Attenuation Compensation

The traveling wave along the long-distance cable system exhibits significant attenuation characteristics in the high-frequency region, resulting in severe peak distortion of positioning curves based on the traditional frequency domain reflection (FDR), especially for the faults which is far from the signal injection end. This phenomenon often leads to misjudgment of cable fault severity. In this paper, the attenuation principle of swept frequency signal along the cable and its influence on the FDR positioning result is analyzed in detail. Based on the traveling wave's attenuation characteristics, to address the above issue, an attenuation compensation function is proposed to improve the FDR algorithm, enabling accurate evaluation of cable's fault severity. Simulation and actual tests on the communication cable and power cable demonstrate that the positioning peaks of the same fault type at the different locations are nearly identical for the optimized FDR positioning curve, with difference less than 3%, which verifies the validation of the improved algorithm.