Faults of composite insulator in service and research of on-line detection method

This paper describes the generation and development process of the carbon tracking fault in the fiber reinforced plastic rod and on the interface between the rod and housing in composite insulators in service. The possibility of the fault has been confirmed by the model tests in the laboratory and the analyses of early operated composite insulators. The fault can be detected on-line by measuring the electric field distribution along the composite insulators. The calculation result and the characteristics of the axial electric field distribution of the faulted insulator are described. Testing results in laboratory are given