Modern Approach to Condition Evaluation of Composite Insulator in Service

It proposes the use of additional test methods for the evaluation of insulating capability and losses of the insulator such as: measuring leakage current, quantifiably evaluating the hydrophobicity using contact angle measurements, evaluating the interface between the FRProd and housing with the combination of water diffusion and pull-off test and evaluating the tightness of the sealing system by prestressing with boiling and dye penetration. The importance of reference values of the material properties in new condition is stressed for the evaluation of the material changes by fingerprinting. Together, the presented test methods provide a comprehensive test program for a holistic condition classification of the composite insulators.

The holistic condition classification system uses a traffic light system and six condition classes.

It provides a generic description and proposes further action for each condition class. The condition class provides an evaluation of the insulator or insulator population at the evaluation time. Therefore, a need for continuous and long-term observation and repeated evaluation of the condition is pointed out. Finally, a case study illustrates the modern evaluation approach and the holistic condition classification on a practical case of the condition evaluation of composite insulators after 23 years of service.