基于雷电冲击特性的同塔多回输电线路并联间隙配置

摘要

As there are large number of phase conductors of multi-circuit transmission line on the same tower,the parallel gaps config-uration for the line is complicated and different configuration mode exhibits different lightning performance. Combined with double-cir-cuit and triple-circuit transmission line on the same tower of Guangzhou Power Supply Bureau,optimal parallel gap configuration scheme for lightning performance of multi-circuit transmission line on the same tower is proposed based on analysis of lightning im-pulse characteristics of insulator strings and lightning protection performance,meanwhile,the lightning protection validity of parallel gaps is also studied. The results show that the lightning impulse 50% flashover voltage of long insulator with parallel gaps is about 80% of that without parallel gaps,and the voltage-time characteristic curve of long insulator with parallel gaps is under that without parallel gaps. The two aspects both indicate good insulation coordination between parallel gaps and insulator. The lightning impulse flashover arc can be led to the air formed by parallel gaps till extinction which proves effective protection of parallel gaps for insulator against lightning. It can be concluded as well that unbalanced insulation configuration between circuits formed by parallel gaps plays an effective role in reducing the lighting simultaneously trip-out rate of multi-circuit transmission line on the same tower.%由于同塔多回输电线路相导线数量多，并联间隙配置方式复杂且不同配置方式下的耐雷性能各异。结合广州供电局同塔双回及同塔三回输电线路，基于对实际运行绝缘子串并联间隙雷电冲击放电特性及耐雷性能的分析，提出了同塔多回线路防雷性能最优的并联间隙配置方案，并研究了并联间隙防雷保护的有效性。结果表明，绝缘子串并联间隙雷电冲击50％放电电压为无间隙绝缘子串的80％左右，前者伏秒特性曲线在后者下方，并联间隙与绝缘子串可以形成良好绝缘配合；试验冲击闪络电弧均可疏导至间隙空气中燃烧，并联间隙有效保护了绝缘子串；同塔多回线路通过并联间隙形成回路间差绝缘，能够有效降低多回同跳概率。