Insulator deterioration caused by what reason?

        Insulators in operation often deterioration, for used in high voltage transmission line suspension insulator is decreased insulation resistance and insulation breakdown, shedding porcelain or crack and surface burn; for pillar insulator, often expressed as the crack or rupture of ceramic column; and the cracking of the pin insulator and often for ceramic head fracture and porcelain petticoat crack or fall off. Insulators, which are often referred to as "zero" or "low", are often referred to as "zero" or "low" insulators.

       The role of the line suspension insulator, one for the suspension of the wire, the two is used to play the role of insulation. As a "zero" insulator strings, sometimes in a string to detection of 2 ~ 3, "zero" is on the part of the insulation is short circuited, accordingly also reduced the insulator string of overall creepage distance, thus greatly increasing the of the insulator string flashover probability. If with "zero" of the insulator string happened flashover, the power frequency short circuit current will be through internal flow through the zero value insulator, strong short-circuit current generated by the thermal effect, often caused by suspended insulator steel cap burst open or disengaged, thus appears insulator fault on power lines, landing a number of serious accidents. In recent years。 Similar accidents in 110 ~ 500kV voltage line has occurred many times.

        In late 1996 to February 1997, in the our country of East China, central China, northwest, North China and Shandong region appeared large area pollution flashover accident involving 500kV lines 15, 330kV lines 2, 220kV line 51, which by the deterioration of porcelain insulator caused insulator string break, lead landing or fall in the tower window accident 26,% 38.23%, to bring heavy losses to the national economy.