A Two-terminal Cable Fault Location Method Based on ISCSO-VMD and NTEO

Abstract

To improve the accuracy and noise robustness of conventional travelingwave- based cable fault location methods under severe noise conditions, a two-terminal travelingwave fault location method is proposed. The proposed method combines variational mode decomposition optimized using Improved Sand Cat Swarm Optimization (ISCSO-VMD) with the Novel Teager Energy Operator (NTEO). A phase-mode transformation is first applied to convert the three-phase signals into modal components and reduce the influence of interphase coupling. ISCSO-VMD is then employed to adaptively decompose and denoise the traveling-wave signals, thereby extracting fault-related highfrequency intrinsic mode functions. Subsequently, NTEO is applied to enhance the transient energy features of the initial traveling-wave front. Finally, the fault distance is calculated using a twoterminal traveling-wave time-difference model. The proposed method is validated using PSCAD/EMTDC simulations. Simulation results for different fault locations, fault resistances, fault inception angles, and noise levels demonstrate stable and accurate detection of the initial traveling-wave front. The relative location error does not exceed 0.43% across all simulated fault cases. In the comparative noise tests, the proposed method maintains more stable initial-wavefront detection than the wavelet-NTEO and EMD-NTEO methods. The improved performance is attributed to the complementary effects of adaptive VMD parameter optimization and transient energy enhancement. ISCSO-VMD suppresses noise and mitigates mode mixing, enabling reliable extraction of fault-related high-frequency components, while NTEO enhances the transient energy features of the initial traveling-wave front and facilitates its detection under low-SNR conditions. However, the practical performance of the proposed method still requires validation on field-installed cables, particularly with respect to cable joints, sheath cross-bonding, measurement bandwidth, propagation-velocity uncertainty, and time-synchronization errors. The proposed method achieves accurate and noise-robust two-terminal traveling-wave fault location by combining adaptive signal decomposition with transient energy enhancement. The results demonstrate its effectiveness under the investigated simulation conditions.