Characterization of Acoustic Signals of Insulation Breakdown in Submarine Cables

To elucidate the temporal and spectral attributes of acoustic emissions arising from high-voltage insulation breakdown in submarine cables, experiments were conducted within an anechoic aquatic environment. A high-voltage pulse was imparted to the cable exhibiting insulation defects through the utilization of a DC high-voltage generator, and the ensuing breakdown signals were meticulously recorded and captured by broadband hydrophones. Comparative analyses were conducted in the temporal, spectral, and time-frequency domains, encompassing signals acquired at various transmission and reception distances. The findings unveiled that submarine cables emit discernible acoustic signals concomitant with insulation breakdown events. These breakdown signals manifest as broadband pulse signals, possessing a temporal duration of approximately 1 millisecond and a frequency spectrum spanning 5 to 130 kilohertz. Notably, the preponderance of energy is concentrated within the bandwidth of 5 to 25 kHz, exhibiting peak frequencies at 8 kHz and 17 kHz. This research inference furnishes pivotal theoretical insights for the expeditious localization of cable faults predicated upon the principles of underwater acoustics.