高压直流输电线路V型串塔头间隙操作冲击放电电压的海拔校正

Altitude Correction of Switching Impulse Flashover Voltage of Tower Gaps With V-shaped Insulator Strings for HVDC Power Transmission Lines

介绍了采用相同结构的真型尺寸V型绝缘子串模拟塔头间隙在不同海拔地区开展操作冲击放电特性对比试验取得的成果。根据在北京和西藏(海拔4 300 m)试验基地获得的塔头间隙操作冲击放电特性曲线,采用插值法计算了海拔4000m及以下地区的塔头间隙操作冲击放电曲线。经分析计算,得出了适合海拔4000m及以下地区高压直流线路塔头间隙海拔校正的计算公式。还将通过试验得出的海拔校正计算公式与目前常用标准IEC 60071-2—1996推荐的海拔校正计算公式进行了对比,分析了两者的修正因子m值的差别及对修正电压的影响。

The results obtained from contrast tests on switching impulse flashover characteristics of tower gaps under different altitudes by two simulation models with true sizes and actual layouts for V-shaped insulator strings are presented. Based on the curves of switching impulse flashover characteristics of tower gaps obtained respectively from test bases located at Beijing and Tibet individually and the latter is at the region with altitude of 4 300 m, the curves of switching impulse flashover characteristics for tower gaps located at the regions with altitudes of 4 000 m and below are calculated by interpolation method. After analysis and calculation, the altitude-corrected calculation formula of switching impulse flashover characteristics curves for tower gaps, which is suitable to the regions with altitudes of 4 000 m and below, is obtained. The comparison of altitude correction computing formula obtained from tests with the formula recommended by IEC 60071-2： 1996, which is common used currently, is performed, and the difference between the values of correction factors m in the two formulae as well as the impact of the two correction factors on switching impulse flashover voltage are analyzed.