Voltage distribution across a string insulator- theoretical and practical study

Summary

In this work voltage distribution was determined both theoretically and practically. A comparison of these two is carried out up to 400 kV System. That is, studies have been carried out both by theory and practice for 33, 66, 220 and 400kV levels. Practical determination of voltage distribution is carried out by sphere gap method. It is well known that there are practical problems in determining the voltage distribution practically. Problems are more when practical determination is carried out for UHV levels, i.e., at 800kV, 1000kV and 1200kV. Therefore, theoretical work of voltage distribution is carried out at 66,132,220 and 400kV levels. The results are compared with practical results. Practical determinations of voltage distribution were repeated several times for confirmation of the results. These results were compared with theoretical ones. The voltage distribution, though they show the same trend of decrease at line end and increase at ground end, the rate and fall of voltages differ at various voltage levels. After obtaining these rate of fall and rise of voltage at various voltage levels, theoretical calculations were made for voltages of 800kV, 1000kV and 1200kV string insulators. This will give an idea of voltage across line end insulators at these voltages, which will help in designing the string insulators for UHV level. This will help the engineers to estimate the voltage distribution and assess the maximum voltage across any given insulator.

Additional informations

Authors

RAMAMOORTY

Keywords

Voltage distribution, String Insulator, UHV, High voltage, transmission