The safety of submarine cable is very important to the power grid. The partial discharge of submarine cable will cause overheating, explosion, electromagnetic interference, power failure and other safety accidents, so it is necessary to detect the partial discharge of submarine cable. When partial discharge occurs, ultrasonic signals are often generated, which can be used for insulation state evaluation and on-line detection. This paper takes 35kV XLPE submarine cable as the research object, and studies the attenuation process of partial discharge ultrasonic signal in the submarine cable through simulation, and completes the charge sensitivity verification of the acoustic sensing device. The results show that the submarine cable model established in this paper can effectively calculate the sound pressure attenuation of partial discharge ultrasonic signal during the transmission of the submarine cable. The relationship between the ultrasonic signal and the phase change of the distributed optical fiber is established, and the phase difference corresponding to the sensitivity of the distributed optical fiber acoustic sensor is calculated to be 20.164.

Submarine cable; Partial discharge; Distributed optical fiber acoustic sensing