A method for detecting conductive droplet deformation and flashover using interface temperature based on electrothermal synergistic mechanism

摘要

Deformation and discharge of water droplets on composite insulator surface are usually accompanied by heat change. This paper aims to seek a method for monitoring droplet appearance and flashover discharge based on interface temperature. It is expected to obtain electrothermal synergistic mechanism in the process of dynamic deformation and discharge of droplets. Fiber Bragg gratings were embedded at the interface of silicone rub-ber-epoxy resin plate specimen to measure interface temperature. A comprehensive test platform of water droplets was established to detect droplet appearance, UV photon number, leakage current and surface infrared temperature. Formation mechanism of high temperature points on hydrophobic surface during droplet defor-mation was proposed. Test results show that leakage current could hardly reflect the droplet appearance. The sudden increase of droplet elongation is accompanied by surface temperature rise. A high temperature point appears near the elongated droplet in electric fields. The maximum surface temperature rise is 3.8 degrees C. As droplet appearance changes or flashover occurs, interface temperature increases. Temperature rise rate during the two stages are 1.19x10(-3)similar to 1.68x10(-3)degrees C/s and 4.46x10(-2)similar to 5.77x10(-2)degrees C/s, respectively. This paper is of great significance for improving the deformation and discharge mechanism of water droplets on the hydrophobic composite insulator surface.