2. Coated cylindrical conductor
For a cylindrical high voltage conductor (r0 =2 cm), the thickness or the radius r1 of a cast resin coating
(?r? = 5) shall be determined so that the maximum field strength in the surrounding air becomes minimal.
The conductor is led in a coaxial air-filled ground conductor (r2 = 10 cm), Figure below. The maximum
field strength in the gas occurs at the surface of the cast-resin coating at r = r1. Using the sweeping
method, use COMSOL software to determine the optimum value for r1. The admissible RMS voltage,
which can be applied to the two electrodes, shall be determined for a maximum permissible field
strength of 200 kV/cm in the cast resin coating and 20 kV/cm in the ambient air.