Analysis of Permittivity and Temperature Effect on Charge Accumulation within Cross-Linked Polyethylene (XLPE) via Numerical Simulation

In general, High Voltage Direct Current (HVDC) transmission is primarily used for submarine applications, including to integrate offshore wind farms to land or to transmit large electrical power over long distances across the sea. Typical insulation used within HVDC cables is either Cross-Linked Polyethylene (XLPE) or Low-Density Polyethylene (LDPE). When a HVDC cable is in service and therefore stressed under DC high voltage, space charge will start to accumulate within the polymeric insulation of the power cable. It is widely accepted that the dynamics of space charge accumulation is as an important element affecting the performance of high voltage cable insulation system. This paper intends to investigate and explain the influence of different permittivity and room temperature on the space charge accumulation within XLPE through a study of numerical simulation. The numerical simulation in this paper was developed based on previous research by R M Hill and J M Alison. Three fundamental equations known as Poisson’s, Transport and Continuity equations, which represent the characteristics of space charge, were employed for the numerical simulation. Preliminary results of the numerical simulation have shown that the variation of these parameters would influence the accumulation behaviour of space charge within the polymeric material.