间插布置绝缘子串的交流冰闪特性

绝缘子覆冰闪络严重威胁电力系统的安全运行。在人工气候室模拟绝缘子覆冰，比较分析了3种间插方式(“2+1”、“3+1”和“4+1”组合)对悬式玻璃绝缘子串冰闪特性的影响。结果表明：间插布置可提高绝缘子串的冰闪电压，其中“3+1”方式较为理想；冰闪电压与绝缘子串长呈一定的非线性关系，常规串的线性度相对较好；冰闪电压与覆冰前绝缘子表面的污秽度(附盐密度)成负指数幂函数关系，间插布置方式的污秽度影响指数小于常规串。通过对试验结果的分析，提出覆冰绝缘子串50%冰闪电压与串长和附盐密度的关系表达式。

AC Flashover Performance of Iced Insulators String Structured With Alternately Large and Small Diameter Sheds

Icing flashover of insulator string greatly threatens the safe operation of power system. Based on the simulation tests of insulators in the artificial climate chamber, the influence of three kinds of insulator strings (two small diameter sheds connected alternately with one large diameter shed, i.e. “2+1” scheme; three small diameter sheds connected alternately with one large diameter shed, i.e. “3+1”scheme; four small diameter sheds connected alternately with one large diameter shed, i.e. “4+1” scheme) on the icing flashover performance of suspension glass insulator strings were investigated and compared systematically, The results show that the icing flashover voltage of insulator string can be improved with the scheme of connecting with alternately large and small diameter sheds (CALSDS), and the “3+1” scheme insulator string is the best. There is a nonlinear relation between the icing flashover voltage and the length of the insulator string and the linearity of the conventional insulator string is the better. The icing flashover voltage is a negative power function against the pollution level before icing covered on the insulator surface. Comparatively, the characteristic exponents characterizing the influence of the pollution level is less than that of the conventional insulator string. By analyzing the experimental results, the relation formula for the length of insulator sting and the salt deposit density and the 50% icing flashover voltages is presented.