中文摘要：

高海拔下操作冲击放电特性是超特高压外绝缘设计的基础之一，也是国内外尚未解决的关键技术之一。由于IEC60-1-1989和GB/T16927．1—1997推荐的g参数法适用范围受到限制，该文选择1m棒-板空气间隙，在人工气候室以及3个不同海拔高度的现场进行试验研究，分析了棒-板空气间隙正极性操作冲击50％放电电压U50与大气参数的关系，提出了基于g参数和基于相对气压的2个新的校正方法，并用试验数据对其进行了验算。结果表明：U50是考虑绝对湿度附加影响后相对气压和空气相对密度的幂函数；IEC标准和国家标准的g参数法不适用于海拔2000m以上和h／δ〉15g／m^3条件下的校正；提出的基于相对气压的校正方法比基于g参数法的校正方法适用范围更广，引起的误差更小。分析计算还表明，湿度增加1g／m^3，引起的U50的变化在1．0％-1．15％之间。

英文摘要：

At high altitude the switching impulse discharge performance of an air-gap is one of design foundations for the external insulation of the extra ＆ ultra-high voltage, also is one of essential technique that did not solved yet. The applicable scope of g parameter law in IEC 60-1--1989 and GB/T16927.1 --1997 is restricted. Therefore, a series of experimental tests in both the artificial climate room and three different altitudes were conducted on lm rod-plane air gap in order to analyze the relationship between the positive polarity switching impulse U50 and the atmospheric conditions. Based on the test results, it proposes two new correction methods based on both the g parameter and the relative barometric pressure, which were checked with the additional test data. The result indicates that, U50 is a power function of the relative barometric pressure and the relative air density with considering the additional influence of the absolute humidity. The g parameter law proposed in both the IEC standard and the national standard is not suitable above altitude 2000m and h/δ〉15g/m^3 conditions. The correction method based on relative barometric pressure has a broader applicable scope and a smaller deviation than that based on the g parameter. The analysis computation also indicates that U50 could decrease 1.0%-1.15% when the humidity increases 1g/m^3.