A Frequency-Domain Location Method for Defects in Cables Based on Power Spectral Density
Zhirong Tang, Kai Zhou, Pengfei Meng, Yumei Li
Abstract
This paper proposes a cable defect location method based on the power spectral density (PSD) to improve the accuracy of existing frequency domain reflection (FDR) method. The principle of the proposed method is that empirical mode decomposition (EMD) is used to decompose the envelope of the reflection coefficient into the intrinsic mode function (IMF) of each insulation defect point and the real part of each IMF signal is windowed. Then, according to the characteristics of a random signal with a definite auto-correlation function, PSD analysis is performed on the IMF signal with limited power. In theory, the power spectrum of a stationary random process is a deterministic function, which transforms the analysis of uncertain signals into the analysis of deterministic functions from the mathematical principle. And combined with the FDR method, localizes the cable insulation defects. Finally, the feasibility and effectiveness of the proposed method are verified by simulation and experiment.