Numerical simulations of ice-covered EHV post station insulator performance equipped with booster sheds

The main objective of this paper is to study numerically the influence of addition of 6 booster sheds (BS) to 2 units of EHV porcelain post insulator on their electrical performance under severe wet-grown ice accumulation based on experimental results. The numerical investigations have been carried out during melting period in order to determine the potential and electric field distributions and the voltage drop along the different air gaps resulting from the addition of BS. Numerical simulations were done using the finite element method (FEM). Adding BS helps to created artificially air gaps which length depends on their position along the ice-covered insulator. Numerical simulations have helped to demonstrate that voltage drop repartition along the different air gap is not uniform. In particularly, it was shown that more that 53% of the applied voltage is concentrated along the first air gap closed to the HV electrode, which also the longest. Also, it was demonstrated that numerical simulations can be useful and an interesting alternative to experimental test in order to improve and optimize the use of BS for improving electrical performance of post insulator under severe icing conditions.