A Non-invasive Defect Detection Method of XPLE Cable Based on PCA and S-transform

In crosslinked polyethylene (XLPE) cables, due to the influence of the dispersion effect, the frequency of the reflected wave is changed with the time of use, meaning there will be interharmonics. The existence of inter-harmonics leads to the existence of false peaks in the location map of defects, which leads to the misjudgment of defects. Moreover, the noise in the measurement environment and the noise caused by the attenuation of the test signal to distortion aggravate the difficulty of defect detection. This paper proposes a defect detection method based on principal component analysis (PCA) and S-transform to extract the main components of the cable-reflected signal to improve the signaltonoise ratio (SNR). Then S-transform are used to accurately locate cable defects. Simulation results show that the positioning error of the proposed method is less than 1%