Reduction of Corona Discharge Using TiO_2 Coating Treatment for High Voltage Transmission Line

摘要

TiO_2 ceramic coating was prepared by plasma spray process. The roughness and contact angle of coated surface were measured. The droplet morphology was analyzed and the corona discharge occurred on the transmission conductor surface under high voltage (HV) electric field was observed by ultraviolet camera. The results showed that by means of spraying TiO_2 coating onto the conductor surface, the reduce in resultant of gravity and electric field force exerting downwards the droplet affixed to the conductor surface led to larger radius of curvature at the tips of water drops. A coarse coating was realized because the surface roughness of the conductor increased from 0.12μm to 5.89μm while the contact angle decreased from 52° to 21.5°. The conductor without coating showed sparks at 50kV while merely sparked occasionally at 80kV for with coating. The wet conductor with coating made considerably less and weaker sparks than the dry conductor without coating.