Fault Localization and Severity Assessment in Power Cables Using Single-Probe Inductive Coupling and Hilbert-Space Decomposition

Soft faults in power cables pose a potential threat to a stable electricity supply. Current reflectometry-based methods provide promising fault location capabilities but can only operate on de-energized systems. This impacts system reliability and increases time and economic costs. This study proposes a method that integrates signal magnetic coupling and Hilbert space decomposition techniques to improve fault detection and assessment in live systems. The method utilizes a single-probe setup that combines an inductive probe and a capacitive equipment (CE) to achieve signal induction-coupled communication. Signal distortion and attenuation arising from the inductive-coupling channel are compensated for by incorporating a physics-based model of the probe and CE into the processing chain. Then, fault localization using Hilbert-space signal decomposition is implemented. Subsequently, a multiple reflection elimination and attenuation compensation algorithm is applied to estimate the reflection coefficient, thereby enabling a quantitative fault severity assessment. Through testing on energized low-voltage power cables under single-fault and triple-fault scenarios in a laboratory environment, the proposed method demonstrates low error rates and robust noise immunity in both location and severity assessment.