An electrostatic study of curvature effects on electric field stress in high voltage differentials

The magnitude of the electric field or electric field stress can become very large in high-voltage applications. These devices must be designed such that the electric field stresses stay well within the material limits for dielectric breakdown. Mathematically, the electric field stress is infinite along sharp edges at interfaces between dielectrics and electrical conductors. Although solid models often assume sharp edges, virtually all components are have a finite radius of curvature. In this investigation, the electric potential and electric field are numerically modelled in a simple configuration with an electrical conductor surrounded by a dielectric material. The effect of the radius of curvature along the edges between dielectrics and electrical conductors on the electric field stress is investigated. •Iterative test and build is costly and time consuming, so efficient computational tools are needed for efficient optimization.•As radius of curvature between a dielectric and electrical conductor increases, the peak electric field magnitude decreases.•For example, increasing the radius of curvature by a factor of six reduces the electric field magnitude by a factor of 2.4.•The magnitude of the electric field along a sharp edge between a dielectric and an electrical conductor is a singularity.•The numerical solution for this singularity increases without bound as the finite-element mesh is refined.