500 kV绝缘横担杆塔电气性能分析

随着国家加大超/特高压输电线路的建设力度,对输电线路杆塔的绝缘性能要求也越来越高。结合绝缘杆塔的国内外研究应用现状,提出绝缘杆塔的结构型式;以绝缘横担杆塔为例,参考500 kV单回路酒杯型杆塔,计算了绝缘横担杆塔和普通铁塔的绝缘水平,并在此基础上分析了两者在电气性能上的差异;从减少绝缘子片数和缩短横担长度2个方面分析了其对绝缘杆塔电气性能的影响。研究结果表明：绝缘横担杆塔在工频电压、操作过电压以及雷电过电压下的绝缘裕度都要高于普通杆塔;要实现绝缘杆塔安全性和经济性的统一,可以在减少绝缘子片数的同时适当缩短绝缘横担长度。

Analysis on the Electric Performance of 500 kV Tower with Insulated Cross-Arm

The accelerated construction of UHV transmission lines by the state brings about, higher insulation performance requirements for the UHV transmission line towers. Based on an investigation of the research and application status of insulation towers, the paper proposes the structure pattern of insulation towers. By taking the insulated cross-arm tower as an example and with a reference to the 500 kV single circuit cup-type tower, the insulation level of the insulated cross-arm towers and the ordinary towers are calculated and the difference of their electrical performances are compared. The impacts of two factors, including reducing the number of insulators and shortening the length of insulated cross-arm, are analyzed on the electric performance of insulation towers. The results show that the towers with insulated cross-arms are superior over the common towers in terms of insulating margin under frequency voltage, switching overvoltage and lightning overvoltage. It can be concluded that number of insulators and the length of the insulated cross-arms may be reduced concurrently to achieve the unification of the safety and economy of insulation towers.