No industry encompasses more companies worlwide than power electric supply. The use of extensive ineterdisciplinary engineering fields, are required in order to generate efficient and high quality energy. The use of larges laboratories and experimental rooms is seems as an expensive
alternative during the design and test of high voltage devices, suach as: isolators, surge arresters, bushings, etc.
In this business, physical prototypes can cost hundreds of thousands of dollars and take months to build. So electric power utilities and device designers are implementing simulation wherever possible to refine designs, catch errors and evalute part and assembly configurations as early
as possible in product development, changes are more easily made.
Problem Description.
The worst enemy for high voltage devices is the deposited pollution in the proximity to the high voltage electrode producing non uniformity of the electric field around and inside of it. Electric strenght and mechanical stresses
can be found on especific points where there are high electric field gradient concentrations.
The following images represent variations on the electric field distribution according to several enviromental changes media. The first case considers
an porcelain isolator with an uniform air core inside (in this case the internal shape is a hollow tube or cilynder). Three metal electrode, High voltage,
intermediate electrode and grounded electrode are included also.
The second case involves the electric field determination for a complete surge arrester. The isolator tube contains both zinc oxide elements and metal spacers
inside.
The purpose is to see how the electric field changes according to the variation of the differents interfaces of material (Porcelain, air metal and Zinc Oxide).
Finally, the most interesting case belongs to a total surge arrester with polluted surface portions. In this case, such polluted portion is allocated at the
upper unit, close to the top of the surge arrester.
