Impact of Voids on Ampacity in High-Voltage Power Cables: A Multiphysical Approach

High-voltage power cables constitute a critical component of the electrical power system, encompassing generation, transmission, distribution, and extending to end-use applications such as electric transportation systems. The power density of such systems heavily depends on the mass of cable arrangement. An efficient cable sizing requires a thorough pre-evaluation of its current carrying capacity or ampacity. The incorporation of voids within insulation layers of cables as a result of manufacturing process have an impact on the cable ampacity. This paper investigates the impact of presence of voids on ampacity in single phase HVAC power cables. A coupled multiphysical finite element model consisting of frequency domain electromagnetic and steady state thermal analysis is presented in this paper. COMSOL Multiphysics software is used for the 2D simulation of cable configuration comprising of 330 KV 50 Hz HVAC cross linked polyethylene (XLPE) cable. The methodology includes the development of a coupled FEA model in association with parametric sweep analysis for the evaluation of the ampacity. The study identifies that the presence of voids creates a non-homogeneity in the temperature distribution and heat flux density distribution within the cable configuration thereby resulting increase in temperature profile by 5% and 2.5% reduction in the ampacity of the aforementioned cable arrangement.