Development and Application of Ultra-low Optical Attenuations OPGW for high Altitude and low Temperature of -55℃

摘要

The ±400kV Qinghai-Tibet DC interconnection transmission line is the first long distance overhead communication line for high altitude, ultra low temperature area in China. According to the technology and application difficulties of this project, we must develop new OPGW with ultra-low optical attenuation and ultra-low additional attenuation capacities. After different tests, we chose ultra-low-loss optical fiber(brief as ULL fiber), ultra-low-temperature resistant optical fiber filling gel and other new materials, designed the fiber excess length and the strain margin properties with new process, and finally developed the OPGW cables satisfying the project requirements, and the optical attenuation of OPGW products was lower than 0.178 dB/km, the average value was 0.172 dB/km, the lowest working temperature is -60 ℃, the additional attenuation was not more than 0.01 dB/km in temperature range of -60℃~+80℃. And we still developed the matched fittings and accessories of OPGW to meet the low temperature requirement. This product has been used well more than one year in this line. It avoided setting up communication relay stations at an altitude of 5000 m plateau, reduced the operation and maintenance difficulties and cost, improved the reliability of communication system, got experience of the longest non-repeater optical fiber communication system's application at high altitude and low temperature areas in China.