Study on operating properties of ceramic long rod insulator for transmission line

AbstractThe material prescription, potential distribution, contamination trend and surface insulating properties under contamination and lightning conditions for the ceramic long rod insulator are investigated. The surface contamination trend of the ceramic long rod insulator can be fitted to an exponential function in a low rainfall area. Potential distribution calculation by three-dimensional finite element method shows that over 50% operating voltage concentrates on the single unit of high-voltage polarity for the long rod insulator string, which is more uneven in comparison with the disc ceramic insulator string. Five-hundred kilovolt full-scale artificial pollution test demonstrates that the contamination flashover voltage of the ceramic long rod insulator has a negative exponential relationship with equivalent salt deposit density and a linear relation with string length. A lightning impulse discharge test confirmed that the relation between 50% lightning impulse discharge voltage and dry arcing dis...