Vibration Fatigue Test and Damage Identification of High-voltage Porcelain Insulator

High-voltage porcelain insulator is widely used in substation, and the seismic performance is very weak. Through the vibration fatigue test of three same types of post insulators, the relationship between the frequency and the load frequency is obtained. Under the action of long-term cyclic vibration load, although insulator appearance inspection is normal, the damage of the insulator is mainly due to the attenuation of flange bending stiffness, which leads to the decrease of the frequency of the insulator in different degrees. In addition, through the establishment of finite element mod-el test of insulator structure, the first two order frequencies of the vibration modes before and after the loading of the insulator are fitted. The bending stiffness coefficient and other parameters of the insulator flange joints are obtained. This not only describes the damage of insulator, but also identifies the location and severity of the damage accurately.