@phdthesis{Challagondla2015, author = {Challagondla, Naresh Kumar}, title = {Behaviour of water drop on the insulator surface and study of electric field distribution on parallel insulators under DC}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-33718}, school = {BTU Cottbus - Senftenberg}, year = {2015}, abstract = {With the recent developments in electrical transmission system, HVDC transmission for long distances has become feasible. With this development, many insulators are being used in HVDC system. Different kinds of insulators are situated at different places (example: desert, near to sea, agriculture area, etc.) so they will get expose to different types of pollution. Pollution affects the behavior of insulation in terms of breakdown and withstand capability. The application experience of insulators under HVDC conditions is limited. There is a necessity to understand the flashover performance and to recognize key parameters in the design and dimensioning of insulators used under HVDC conditions. This dissertation presents the difference between the analysis of partial breakdowns at AC and DC. The dissertation explains the behavior of a water drop on insulator shed surface energized with DC. It deals with the moving water drop and hanging drop at the edge of the shed. There are many situations where insulator structure should be in parallel. For example, the structure of insulators in vertical disconnector equipment often is parallel. If insulators are arranged in parallel, then the behavior of the electric field is totally different. It is important to know the behavior of these insulators used in HVDC system. This report also explains the pollution and non-pollution behavior of parallel insulators energized with DC. The results can be a source of information to optimize the design and dimensioning of HVDC insulators, especially in pollution conditions.}, subject = {HVDC; High-Voltage insulators; Pollution performance; Water drop behavior; Parallel insulators; Ansys Maxwell; HG{\"U}; Hochspannungsisolatoren; Verhalten bei Verschmutzung; Verhalten von Wassertropfen; Parallele Isolatoren; Hochspannungsisolator; Wassertropfen}, language = {en} }