摘要
电气结构设计是110 k V格构式复合材料杆塔应用所关注的焦点问题,其重点在于如何提高防污和防雷性能。首先针对杆塔复合材料的绝缘特性进行了分类、分项测试,结果表明E型玻璃纤维增强型环氧树脂复合材料满足绝缘材料电阻特性要求,可用于制作绝缘杆塔。结合考虑断线张力等因素,通过污秽试验和电场仿真计算,确定了横担采用格构式横担悬挂加装均压环的FXBW-35/70防污型复合绝缘子的防污设计,试验表明,其污耐压高达145 k V。杆塔防雷须采用架设避雷线、且通过接地引下线逐塔接地的方案;针对复合材料被电弧烧蚀后易失去绝缘性和结构强度的特点,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。结合理论计算,获得了110 k V双回线路格构式复合材料杆塔的雷电性能,与同电压等级铁塔相比,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20Ω条件下,杆塔的耐雷水平提高了94%,而雷击闪络跳闸率降低了82%。综上,110 kV双回线路格构式复合材料杆塔采用提出的电气结构设计,具有更好的防污和防雷性能。
Electrical structure design is the core of lattice composite material tower of 110 kV double circuit line applied in the regions of serious pollution and intense lightning activity, focusing on pollution and lightning protection design. First, the insulation characteristics of the composite material are classified and tested by separate items. The test results show that the composite material of e-glass fiber enhanced epoxy resin meets the demand of resistance characteristics of insulating material. And considering some factors such as wire tension, through pollution test and electric field simulation, the anti-pollution design is determined as lattice cross arm with type FXBW-35/70 composite insulator. The test result shows the pollution flashover voltage reaching to 145 kV. The design scheme of erecting of lightning shielding line and the grounding down line should be applied in the lightning protection of the tower. According to the character of the composite material tower head easily losing insulation and strength by the arc ablation, the grounding-down mode have been put forward, with the grounding line vertically suspended along phase conductors on the center line between the two circuit lines. Then, the distances of grounding down line from tower and the phase conductor cross arm from steel tower body, as well as lightning impulse dielectric strength U50%, of tower, are determined by lightning impulse tests of true type tower head. Finally, The lightning performance of lattice composite material tower of 110 kV double circuit line is obtained through the theoretical calculation. Compared with lightning performance of the steel tower of the same voltage level, U50% of lattice composite material tower of 110 kV double circuit line is increased nearly 1.14 times than steel tower, and under the condition that the grounding resistance is 20 ohms, the lightning withstand level is increased by 94% times than steel tower, while lightning flashover trip rate decreased by 82%. In one word, lattice composite material tower of 110 kV double circuit line applying the electrical structure design put forward in this paper has much better performance in pollution and lightning protection.
出处
《电网技术》
EI
CSCD
北大核心
2015年第2期536-542,共7页
Power System Technology
关键词
复合材料杆塔
污秽性能
污耐压:接地引下方式
雷电性能
composite material tower
pollutionperformance
pollution flashover voltage
grounding-downmode
lightning performance
