Research on Live Detection Technology of Insulation State of Distribution Network Cable Based on Harmonic Components

As a new diagnostic technology of live detection for power cables, the diagnostic method of harmonic detection in power cables has important theoretical significance and application value to improve the reliability of power cable detection and diagnosis. This paper summarizes the research progress of the diagnostic method of harmonic detection in power cables at home and abroad, systematically analyzes the advantages and disadvantages of cable harmonic detection methods, and then puts forward the live detection method based on harmonic components. Firstly, the magnetic flux evolution of cable insulators with typical defects is obtained by electromagnetic simulation. On this basis, the relationship between the harmonic content obtained by live detection and aging and moisture defects of cable is studied. Based on the harmonic characteristic data under the condition of deterioration, a diagnosis method of deterioration and dampness in distribution network cable is constructed by using cluster analysis and linear regression analysis. Experimental verification shows that the live detection method and evaluation method of distribution network cables proposed in this paper can effectively detect high-risk cables with latent defects.