Electric Fields Distribution of 500kV AC Transmission Line V-type Composite Insulator with Conductive Defect

The accurate detection of the defective composite insulators is vital to the safety of the transmission line in the power system. The defects distribution in the V-type insulator strings is more complex than that in the I-type insulator strings, which brings many difficulties to the accurate on-site detection of the defective insulators. In this paper, the three-dimensional models 500kV AC transmission line V-type composite insulator strings with the internal conductive defects were established with the application of the finite element method. The electric field distribution of the normal insulators and the insulators with conductive defects were calculated. The influences of the defects length and position parameters on the electric field distribution of the insulators were also analyzed. The calculation results show the electric field distribution will appear distortion apparently when the conductive defects exist in the insulators. The electric field distribution characteristics of the V-type insulator srtings with the different defect lengths and position parameters can be directly applied to the accurate field detection of the defective composite insulator.