CST EM STUDIO® (CST EMS) offers the possibility to perform parameterized electrostatic simulations of high voltage or insulating devices such as a transformer bushing. Furthermore, the electrostatic solver supports both hexahedral and tetrahedral mesh types.
Figure 1 shows the construction of the bushing comprising of a central conductor, a ceramic insulator, and a housing containing the transformer oil.
The structure was created using the powerful modeling tools in CST EMS. The bushing was created by sweeping over 360 degrees a curved profile. To complete the bushing geometry, the blend tool can be applied to round off the bushing edges.
The permittivity of the ceramic has been set to 1000 with an epsilon of 2.9 for the oil. The housing and the central conductor were both defined as perfect electric conductors (PEC)....
Symmetry is exploited via the use of tangential symmetry conditions and an open boundary has been applied to reduce the simulation domain.
In CST EMS arbitrary potentials can be applied to parts of the geometry and this can be seen in figure 2 where it suffices to specify the potential on the central conductor only.
The simulation was perfomed with the aid of the adaptive meshing scheme in CST EMS. This eliminates any question of discretization effect on the results which can be seen in figure 3. The electrostatic potential on a central cutting plane is plotted in both contour and isoline form. Note that the use of Open Boundary conditions leads to a significant reduction in the required simulation domain volume. In addition to the potentials, the Electric Field Intensity and Electric Flux Density are available which may also be combined or further processed using post-processing templates. Fields on curves and surfaces may also be plotted or integrated.
With its extensive CAD import and export facilities, easy-to-use interface, built-in parameterization and optimization modules, and post-processing templates, CST EMS is a very powerful tool for the simulation of electrostatic devices. Other modules are also available for the analysis of magnetostatic, low frequency, stationary current flow and stationary temperature problems.