超/特高压线路空气间隙电气特性试验中的若干问题

Several Problems on Air Gaps Flashover Characteristics Tests for EHV/UHV Transmission Lines

为了获得超/特高压线路杆塔间隙在各种影响因素下的闪络特性,满足线路绝缘配合需要,提高线路运行的安全性和经济性,依据超/特高压线路空气间隙电气特性试验结果,分析了冲击电压极性、间隙电极结构、杆塔宽度、导线结构、"邻近效应"等因素对空气间隙放电电压的影响,以及操作冲击放电特有的性能。结果表明杆塔宽度、导线结构、接地体"邻近效应"对闪络电压影响明显,如杆塔宽度增大,相等间隙距离冲击闪络电压降低,且随着间隙距离的增大,塔宽的影响逐渐减小;在相近条件下8分裂导线空气间隙的放电电压与4分裂导线的放电电压相比,最大相差约10%。

In order to get flashover characteristics of tower gaps for EHV/UHV transmission lines under different factors,supply the parameters for insulation co-operation,and increase the security and economical efficiency,this paper analyzes the influence from impulse voltage polarity,electrodes structure,tower width,conductor structure and the proximity effect to the flashover voltage,based on the test results of tower gaps flashover characteristics for EHV/UHV transmission lines.The results indicate that influence from tower width,conductor structure,proximity effect is remarkble.For example,when tower width increases,the fashover voltage will reduce,but with gap distance＇s increasing,the influence to the flashover voltage will decreases.The flashover voltage of air gap with 8-conductor bundle is 10% higher than the one with 4-conductor bundle,when other test condition is the same.In the paper,corresponding better solution is put forward for the air gaps discharge test.