New designs for H.V. insulators with reference to desert conditions

This paper describes the results of extensive experimental work for assessment of the performance of newly designed H.V. porcelain insulators under desert conditions. Six different designs of suspension-type insulators of the same diameter and of almost equal leakage paths were proposed and produced using zero porosity high grade porcelain. Artificial and natural pollution tests are carried out on the different shapes according to IEC standards. Dry insulators, clean-fog wetted insulators, and salt-fog wetted insulators were tested. The natural pollution tests were carried out after 12 months of exposure on a 20-meter — high tower sited in the "Pyramids High Voltage Research Center", Cairo West, which is an ideal position for simulating desert conditions. The metreological conditions during the exposure time were recorded and found to simulate closely the average conditions during the last five years. Analysis of the different test results lead to the most suitable insulator design for desert conditions in Egypt.