Electric field modelling of HVDC glass insulators preliminary findings from insulation strength studies

The integrity of the insulation of overhead power lines is an important factor in view of safety, particularly in the context of live line maintenance. Where broken glass disks need to be replaced under energized conditions, the reduction in the withstand strength will dictate the approach towards live line techniques to be applied. Initial findings from the electric field modeling of a glass insulator string with and without broken disks are presented in this paper. The findings of the field modeling agree well with that from laboratory tests and yield confidence in the model that will be used for further studies.