In the urban distribution network, cross-linked polyethylene (XLPE) power cables are widely used because of their many advantages, and their insulation state affects the safe and reliable operation of the system. In the cable from the operation of the power grid to the scrap has a certain service life, different service length of the cable will be in different aging states, so it is particularly important to study the propagation characteristics of the partial discharge signal under different aging degrees. In order to obtain accurate partial discharge signal propagation characteristics, it is important to establish a refined cable model. In order to obtain a refined model of XLPE power cable, the cable structure is first analyzed according to the physical object, and the equivalent impedance, capacitance and inductance are calculated with the help of comsol simulation software. Secondly, the degree of aging of the cable has a certain correspondence with its frequency domain dielectric parameters, so different cable frequency domain dielectric parameters can be set to approximate the partial discharge propagation characteristics of the cable under different aging degrees. According to the simulation results, the partial discharge signal shows different propagation characteristics in cables with different aging degrees, and the attenuation of the signal amplitude gradually increases with the increase of the static dielectric constant. Therefore, it can be known that as the degree of cable aging increases, the attenuation of the partial discharge signal in the cable is greater. The propagation characteristics of the partial discharge signal in the cable under different aging conditions are not the same. Therefore, when conducting partial discharge tests on cables, it is necessary to consider the service time of the cables, so that the measured values obtained are closer to the actual discharge.
 

aging,XLPE cable,partial discharge,propagation characteristics