抄録
In HVDC transmission lines, hydrophobicity losing could occur even on well designed insulators, which causes the essential concern on the electrical accidents induced by the ageing of silicone rubber (SiR) insulators. Much attention has been paid on the accurate evaluation on the insulator hydrophobicity for the long-term performance of outdoor insulators in service. In this paper, based on dynamic dropping test (DDT), the acoustic characteristic of surface discharges was investigated to evaluate the hydrophobic properties of SiR insulator at different ageing degrees under dc voltage stress. The obtained results indicate that the acoustic characteristic of discharge is sensitive to the hydrophobic properties, which can be applied as a non-contact method for the hydrophobicity evaluation of HVDC insulators.
