Partial discharge-based ageing assessment of high voltage crosslinked polyethylene cable

• DOI: 10.4314/njtd.v21i4.2351
• Publication Date: 2025-02-20T13:53:17Z
• Authors: S. H. Sulaiman; A. Abdulkarim; A. S. Abubakar; G. S. Shehu; U. Musa; A. A. Mas’ud

High Voltage (HV) cables are important components of modern power transmission and distribution networks. However, the reliability of such networks depends, to a large extent, on the health condition of the cables. The presence of voids within the insulation materials which could arise from overstressing, manufacturing defects as well as poor workmanship enhances the electric field within and around the defect which can lead to the occurrence of partial discharges (PDs). Furthermore, severe PD activity can deteriorate the cable dielectric material and cause accelerated asset ageing. Also, experimental monitoring of cable networks is expensive and time-consuming. Hence, in this research, a three-dimensional (3D) finite element model (FEM) of a crosslinked polyethylene (XLPE) cable was simulated in COMSOL Multiphysics software environment to analyse the behaviour of electric field in healthy and defective cable under different cavity sizes and applied voltages. The electric field magnitude at the centre of a 1.0 mm air void was recorded to be 2.539 kV/mm, representing a 24.07% increase over that of the corresponding healthy cable, 2.9539 kV/mm. PD activity was also studied using COMSOL Multiphysics software alongside MATLAB software environment by adopting free parameters corresponding to three ageing phases of the cable obtained from experiments for 50 cycles of the applied voltage. The results show that PD repetition frequency increases as the cable ages, resulting in 9.82, 15.82, and 17.20 PDs per cycle for ageing stages 1, 2, and 3 respectively.