串长及布置方式对高海拔覆冰绝缘子串直流冰闪电压的影响

高海拔覆冰地区绝缘子选择是特高压直流输电工程面临的技术难题之一，国内外对此研究甚少。该文在人工气候室模拟高海拔和覆冰环境，试验研究了XZP-210直流绝缘子串在轻覆冰时的冰闪特性，分析了冰闪电压与串长和布置方式的关系。结果表明：在不同污秽程度和气压下，轻度覆冰绝缘子串的正、负极性直流闪络电压与串长基本呈线性关系，但存在小于10%的非线性度，且污秽越严重或气压越低，非线性度越小；绝缘子串的布置方式对冰闪电压有明显影响，水平布置时冰闪电压最高，V型串次之，垂直串最低；气压对水平布置的绝缘子串冰闪电压影响最为严重，V型串次之，悬垂串最小。

Influence of Length and Arrangement of Iced Insulator Strings on DC Flashover Voltage at High Altitude Districts

Insulator selection in high altitude and icing regions is one of the key technical issues of UHV DC transmission project. Up to now, both at home and abroad, there is very little research on it. The high altitude and icing environment were simulated in the artificial climate chamber. The flashover performance of ice-covered XZP-210 insulator strings was investigated and the effects of the string length and anangement on the icing flashover voltage were analyzed. The results show that there is a linear relationship between the icing DC flashover voltage and the insulator string length. The non-linearity is less than 10% and decreases with the increase of the altitude and the pollution level. The arrangement of the insulator string has obvious influence on the icing flashover voltage. For various arrangements, the icing flashover voltage of the horizontal string is the highest, the V-type string takes the second place, and the vertical string is the lowest. The effect of the air pressure on the flashover voltage of the horizontal string is most obvious, the V-type string takes the second place, and the influence on the vertical string is the lowest.