输电线路激光除冰技术试验分析及工程应用设计

Experimental Analysis and Engineering Designing of Laser De-icing Technology for Transmission Lines

为防止覆冰对输电线路的危害,从理论分析、模拟试验、工程应用设计等方面系统研究了输电线路激光除冰技术,分别得出了CO2、Nd:YAG激光除冰特性:1.5kW CO2激光融冰体速度约为728.5mm3/s,单位能耗为2.08J/mm3;Nd:YAG固体激光融冰效果稍高于CO2激光,突出优点在于其热应力除冰;激光除冰时瓷绝缘子安全阈值约20.5～54.4J/mm2,复合绝缘子远小于该值,导线安全阈值很高,几乎不会损伤。结果表明激光可用于输电线路除冰,具有热融冰效应和热应力效应,如结合机械除冰可大大提高除冰效率和效果。根据研究结果提出了其工程应用设计方案:工程化车载式激光除冰系统选用固体激光器,输出功率1～1.5kW,光斑直径15～20mm,发散角3mrad,作用距离为100～1000m,激光电源采用车载发电机,总功耗≤50kW。预计未来3～5a激光除冰速度将可提高3～4倍,激光除冰系统可向小型化、便携式方法发展。

Laser de-icing for transmission lines is a novel technology which has a good future for engineering applica- tions. We studied this technology through theoretical analysis, simulation experiments, and engineering designing. Laser is capable of de icing for transmission lines, and laser has the effects of melting ice and generating stress inside the ice, and the latter would achieve an excellent de-icing effect if combined with the mechanical de-icing technology. Laser de-icing technology for transmission lines have many advantages, such as long distance, non-contacting, adsc- ititious heat source, not adding equipment in power system, not cutting power. Two most developed and applied la- ser technologies, CO2 laser and Nd：YAG solid laser, were mainly chosen to carry out the de-icing simulation experi- ments. The experimental results show that CO2 laser Only has the effect of melting icing, and the de-icing effect is determined by the laser parameters of power, spot size, incising velocity, etc. The volume velocity and energy cost of melt icing on conductors with the power of 1500 W are 728.5 mm^3/s and 2.08 J/mm^3 , respectively, with the help of lightly knocking, they would be changed to 38 595 mm^3/s and 0. 0389 J/mm^3. Nd：YAG solid laser has a little better melting ice effect than CO2 laser, while the most remarkable advantage is generating stress inside the icing, which makes the icing very easy to remove with mechanical means. When applying laser de-icing technology, insulators and conductors have safety threshold values （STV）. The experiments show that the STV of porcelain insulator is about 20.5-54.4 J/mm^2 , and that of composite insulator is far smaller, while the conductor has a very large STV and could hardly be damaged by laser. Consequently, a truck-carried laser de-icing system for engineering application was designed, which adopted solid laser with the power of 1-1.5 kW, spot diameter of 15-20 mm, radiation angle of 3mrad, and acting distance of 100-1000 m. The system was also capable of de-icing for transformer substation.