【摘要】 应用复合材料杆塔需要经济的、适于杆塔材料和结构特点、并能有效提高杆塔雷电性能的雷电防护设计方案。为此,以110 kV线路杆塔为目标,首先从电气要求和经济成本方面考虑,提出了由复合材料塔头和金属角钢塔身组合而成"半绝缘结构格构式复合材料杆塔"的设计方案。针对该结构的复合材料杆塔,分析了避雷线和接地引下线的架设与否对线路雷电性能的影响,提出了杆塔应采用架设避雷线、且通过接地引下线逐塔接地的防雷方案。针对复合材料被电弧烧蚀后易失去绝缘性能和结构强度的特点,提出了沿导线方向在两回线路中心线上竖直架设引下的方式。然后,开展了复合材料真型塔头雷电冲击放电试验,确定了引下线离塔身距离和下相横担离金属塔身距离,以及杆塔雷电冲击绝缘强度。通过理论计算,获得了110 kV双回线路格构式复合材料杆塔的雷电性能。计算结果表明:与同电压等级铁塔雷电性能相比,复合材料杆塔雷电冲击绝缘强度提高了近1.14倍;在接地电阻为7Ω和20Ω条件下,杆塔的耐雷水平分别提高了81%和94%,雷击闪络跳闸率降低了71%和82%。更多还原

【Abstract】 Composite materials applied in power transmission grids requires should be economic, suitable for the towers’ structure and effective in improving the towers’ lightning performance. Taking the electrical requirements and cost containment of 110 kV transmission lines as examples, we put forward a design of lattice composite-material tower with a semi-insulating structure. In the design, a tower consists of a head made of composite materials and a body made of metal angle steel. On the basis of the proposed tower design, we analyzed the influences of lightning shielding line and grounding down line on the tower’s lightning performance, and obtained that the lightning protection scheme should have the towers equipped with lightning shielding lines that are grounded through grounding down lines at each tower. Since composite materials affected by arc ablation could easily lose electrical insulation and structure strength, we proposed to set up the grounding down lines to vertically suspend along phase conductors on the middle line of two-circuit lines. Then, we tested lightning impulse on true-size tower head of composite material to determine the distance between grounding down line and tower, the distance between phase conductor cross arm and steel tower body, and the tower’s lightning impulse dielectric strength. We also theoretically calculated the lightning performance of the lattice composite tower on 110 kV double-circuit lines. The results indicate that, compared with that of regular 110 kV steel towers, the lightning impulse dielectric strength of the lattice composite material tower increases by nearly 1.14 times; when the grounding resistance is 7 Ω and 20 Ω , respectively, the lightning withstand levels of the tower increase by 81% and 94%, and lightning flashover trip rates decrease by 71% and 82%.更多还原