Mechanism of Pollution Discharge Caused by Suspended Potential Conductor on the Surface of Composite Insulating Materials

To analyze the mechanism of discharges near the suspended potential metal bolts in the contamination test of composite insulating material towers, the intermittent discharge caused by the suspended potential conductor was reproduced on the composite insulation material test strip. The quasi-electrostatic field method was used to simulate and analyze its electric field distribution. On the one hand, the presence of suspended potential metal bodies on the contaminated surface causes the electric field on the contaminated surface to be distorted. Electric field distortion is the fundamental cause of partial discharge. On the other hand, the current density in the surrounding pollution layer is increased, resulting in a further increase in the electric field strength. The distortion electric field decreases rapidly as the length of the dry belt increases after corona discharge, which limits the extension of the dry belt. The intensity of the partial discharge that appeared intermittently changes significantly. The mechanisms of the occurrence and development of the discharge phenomenon caused by the suspended potential metal body are proved.