In the sound filed simulation of existing electric facilities

the common frequency domain simulation only focus on the distribution of energy in the post-propagation. Time-domain simulation

on the other hand

focus more on the energy propagation processes in the early stage. Therefore

when modelling the ultrasonic signal of partial discharge of submarine cables

the complex refraction and reflection processes are more suitable to time-domain simulation in the early stage of signal radial propagation. As for the single phase XLPE submarine cable in this paper

a full-size slice model containing totally such 11 layers of structures as copper core

semi-conducting shield and insulation layer etc is set up. The time-domain simulations are used to obtain the radial propagation processes of the ultrasonic signal through the multi-layer structure of a submarine cable. During the propagation processes

the ultrasonic signal of partial discharge is refracted and reflected several times to form a multi-frequency non-periodic signal with superimposed longitudinal and transverse waves. Due to the influence of refraction and reflection

energy is gradually released outwards between the material layers

inducing core strains in the outer fiber units close to pico-strain. The radial propagation of ultrasonic signals in submarine cables due to partial discharge at three different locations is compared

which provides theoretical guidance for the detection of partial discharge ultrasonic signals by embedded optical fiber sensors in submarine cables.