Research on shed crack of composite insulators used in strong wind area

Composite insulators promoted development of ultra-high voltage transmission lines and study of the composite insulators is a very important topic at the electric engineering. For the wide area and variable weather of China, the composite insulators will endure several terrible conditions. Strong wind area is very special environment at China or the worldwide. Now the transmission lines problems caused by are mainly focusing on the tower strength, conductor galloping and external insulation selection. The sheds cracks of the composite insulators at 750 kV AC lines in Xinjiang province is very new topic. It is found that when the wind speed is higher than 30 m/s, the biggest sheds of the tested composite insulator would vibrate at high frequency and great amplitude. This paper obtained the reason of the shed crack at high speed wind. With the ANSYS simulation, the process between the strong wind and the sheds of composite insulators was studied. The mechanical properties were researched. To indicate the mechanical properties of HTV materials, we tested several composite insulators used in 750 kV lines. The tearing fatigue strength of HTV should be considered as one important factor when select the HTV.