高海拔真型塔110kV绝缘子雷击闪络试验及判据研究

由于高海拔地区雷击跳闸严重,且近年来同塔双回线路逐渐增多,有必要针对高海拔地区同塔双回输电线路开展耐雷性能精确分析方法和防护方法研究。而绝缘子雷电冲击闪络判据是输电线路耐雷性能分析的关键模型之一。因此,论文针对绝缘子雷电冲击闪络先导发展模型中仍缺少高海拔地区、同塔双回真型塔绝缘子闪络特性的试验数据及其先导发展模型参数的现状,在海拔2100 m的国家工程实验室户外试验场开展了同塔双回真型塔110kV复合与玻璃绝缘子雷电冲击试验。主要研究在1.2/50μs标准雷电冲击及1.0/10μs短尾波冲击下,不同绝缘子的闪络路径、50%冲击放电电压和伏秒特性差异。根据冲击发生器产生的真实电压波形和绝缘子闪络试验结果,基于对不同长度绝缘子先导通道场强特点分析,提出了最优拟合度的高海拔地区真型塔110kV复合和玻璃绝缘子先导发展模型参数。并分析解释了冲击电压波形参数、冲击电压极性以及绝缘子材质对先导发展模型参数k、E0和El的影响。经验证,文中先导发展模型及参数用于高电压等级绝缘子及长空气间隙时有误差,且电压等级越高,误差越大。所得结论可为精确的高海拔地区110k V同塔双回输电线路耐雷水平计算及外绝缘设计提供参考。

Lightning Flashover Performance Test and Flashover Criterion Study of Insulators in a 110kV True Type Tower at High Altitude Areas

Due to severe lightning strikes at high altitudes and increase in number of double-circuit transmission lines,it is necessary to carry out research on accurate analysis methods and protection methods of lightning resistance for double-circuit transmission lines in high altitude areas.Insulator flashover criterion under lightning impulse is one of key models of lightning resistance performance analysis of transmission lines.Due to lack of experimental data about insulator flashover characteristics and parameters of its leader propagation model in double-circuit transmission tower in high altitude areas,lightning impulse flashover tests of two types of insulators(composite and glass insulators)was carried out in National Engineering Laboratory(Kunming)for Ultrahigh-Voltage Engineering Technology.Lightning impulses in the tests included standard lightning impulse(1.2/50μs)and short tail lightning impulse(1.0/10μs).Differences in discharge paths,50%impulse flashover voltages and volt-second characteristics under different conditions were studied.According to actual voltage waveforms generated with impulse voltage generator and insulator flashover test results,based on analysis of electric field of leader channels with different insulator lengths,optimal fitting parameters for leader propagation model of 110 kV composite and glass insulators in a true type tower at high altitude were proposed.Influences of the parameters of impulse voltage waveform,voltage polarity,and insulator material on model parameters k,E0,and El were analyzed and explained.The leader propagation models and parameters in this paper had errors when used in high voltage insulators and long air gaps.The error became higher with increase of voltage level.The conclusions can provide references for calculation of lightning resistance level and external insulation design of 110 kV double-circuit lines at high altitude areas.