Online Hydrophobicity Measurement for Silicone Rubber Insulators on Transmission Lines

This paper presents an online hydrophobicity measurement technique for silicone rubber (SIR) insulators on transmission lines and its field test results. Based on the hydrophobicity classification (HC) method, an online hydro-phobicity measurement device was developed, which consists of a controllable sprayer, a video camera and a hydrophobicity analyzing software. Online hydrophobicity inspection was conducted for the polluted SIR insulators on three ac transmission lines in the north of China for more than one year by using the device. Some SIR insulators operated for 8 years were analyzed in the laboratory by using the scanning electron microscopy and the infrared spectroscopy. The results show that the surface hydrophobicity of the SIR insulators varies remarkably with seasons. We also find that the microstructure of the pollutants significantly influences the hydrophobic transfer, and that the aging phenomena happen on the surfaces of the weather-shed materials of the SIR insulators operated for 8 year. It is proposed to strengthen the hydrophobicity inspection for the SIR insulators in service.