Performance of composite insulators without sheds under light pollution

Abstract: The test of insulators without sheds or with small sheds number at Glogow pollution station was described. The performance of insulators with different leakage distance and position (horizontal or vertical) under light pollution is studied. The flashovers, leakage currents and surface erosion were monitored. The 75 kV test voltage is 4 kV higher than the maximum phase to ground voltage of 110 kV system. After long term testing the leakage distance of 80 cm was found as withstand distance for horizontal rods and 100 cm for vertical rods. For practical purposes the security factor of 1,3 should be taken into account. Finally, under light pollution the 110 kV composite insulators in horizontal position could be installed in the form of 100 cm long rods without sheds and vertical insulators with terminal distance of 100 cm should have at least two additional sheds.