Optimisation of high voltage equipment design using boundary element method based electromagnetic analysis tools

The pressures of bringing new products to market faster make tools that enable engineers to design and optimise devices and components with more exact information and shorter prototype cycles indispensable. This paper discusses an approach to design tools for high voltage engineering based on the boundary element method in two and three dimensions. Such tools allow an industrial user to obtain general information about the electrostatic fields in the vicinity of a high voltage device. Optimisation of the device is performed using an iterative method of refining a design and re-analysing without having to resort to repeated prototype building and testing. In this paper, a general overview of boundary element theory as applied to electrostatic analysis in two and three dimensions is given. Some solution strategies using boundary element method analysis tools are introduced. Demonstration of the analysis tool is provided via the practical example of an epoxy rod between two coaxial electrodes in which the electric field distribution (around metal inserts, high voltage shields and along the creepage distance) is required. In this example, two-dimensional analysis of the rotationally symmetric model provides a starting point for analysing the device. The rotationally symmetric model cannot fully account for the true geometry of the device and therefore a three-dimensional analysis is performed as a final step in the verification process