A Method and System for Diagnosing Interface Defects in Power Cables Based on High-Frequency Oscillating Wave Detection

Abstract

This invention relates to the field of power cable insulation condition detection technology, specifically disclosing a method and system for diagnosing interface defects in power cables based on high-frequency oscillating wave detection. The method involves acquiring a composite time-domain signal at the cable test end; performing variational mode decomposition on the composite time-domain signal to extract the component with the highest center frequency as a candidate discharge pulse group; performing convolutional sparse decomposition on the candidate discharge pulse group and a defect-free reflection waveform template set to extract a pure partial discharge pulse waveform and its reflection path delay value; inputting the delay value into a particle swarm optimization objective function to inversely determine the specific joint or branch node where the defect is located; finally, counting the number of pulse recurrences in each phase interval, and determining the existence and location of the defect after median filtering. This invention can accurately separate aliased signals and precisely locate interface defects in multi-branch, multi-joint topologies.

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